Multilayered packaging articles and associated coatings

Abstract

Multilayered articles for consumer packaging, as well as associated coatings, methods, systems, and apparatuses are generally provided. In some embodiments the disclosure relates towards barrier coatings (e.g., multilayered barrier coatings) with favorable combinations of properties for sustainable consumer packaging. The disclosure further relates to spatial atomic layer deposition (SALD) as a technique for forming barrier coatings.

Description

[0001] MULTILAYERED PACKAGING ARTICLES AND ASSOCIATED COATINGS

[0002] RELATED APPLICATIONS

[0003] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63 / 693,083, filed September 10, 2024, and entitled “MULTILAYERED PACKAGING ARTICLES AND ASSOCIATED COATINGS,” U.S. Provisional Application No. 63 / 705,440, filed October 9, 2024, and entitled “MULTILAYERED PACKAGING ARTICLES AND ASSOCIATED COATINGS,” and U.S. Provisional Application No. 63 / 796,771, filed April 29, 2025, and entitled “MULTILAYERED PACKAGING ARTICLES AND ASSOCIATED COATINGS,” which are incorporated herein by reference in their entirety for all purposes.

[0004] TECHNICAL FIELD

[0005] The use of barrier coatings for consumer packaging is generally described.

[0006] BACKGROUND

[0007] Barrier coatings are used in some packaging to reduce spoilage of packaged products. However, the most effective barrier coatings are typically not recyclable or compostable, and alternatives can be difficult to apply in bulk. Improvements to the cost and performance of barrier coatings would be advantageous.

[0008] SUMMARY

[0009] Multilayered articles for consumer packaging, as well as associated coatings, methods, systems, and apparatuses are generally provided. In some embodiments the disclosure relates towards barrier coatings (e.g., multilayered barrier coatings) with favorable combinations of properties for sustainable consumer packaging. The disclosure further relates to spatial atomic layer deposition (SALD) as a technique for forming barrier coatings.

[0010] The subject matter of the present disclosure involves, in some cases, interrelated products, alternative solutions to a particular problem, and / or a plurality of different uses of one or more systems and / or articles. In one aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, wherein the layered article is recyclable or compostable.

[0011] In another aspect, a layered article is provided. According to some embodiments, the layered article comprises: a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, wherein the barrier coating has two or more of the following properties: (i) a ratio of A1OXto ZnOyof greater than or equal to 1:2 and less than or equal to 5:2; (ii) a ratio of A1OXto SiOzof greater than or equal to 1:2 and less than or equal to 5:2; (iii) an oxygen transmission of less than or equal to 25 cc / m2-day and, has a water transmission of less than or equal to 10 g / m2-day, and is transparent; (iv) at least 30 layers of the first layer and at least 30 layers of the second layer; (v) wherein the substrate comprises pinholes having an average diameter greater than or equal to 25 nm, but the barrier coating is substantially pinhole free; and (vi) wherein the substrate has an RMS roughness of greater than or equal to 5 micrometers but the thickness of the barrier coating varies by less than 100% from an average value of the thickness of the barrier coating.

[0012] In yet another aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer, wherein the substrate layer comprises paper having an average pinhole size of less than or equal to 25 nm; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer.

[0013] In still another aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer; a barrier coating adjacent the substrate layer; and a sealant layer adjacent the barrier coating, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, and wherein the sealant layer is configured to be fused to itself to form a seal. In another aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer; a barrier coating adjacent the substrate layer; and a primer layer disposed between the barrier coating and the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, and wherein the substrate comprises pinholes having an average diameter greater than or equal to 25 nm, but the primer layer comprises pinholes having an average diameter of less than or equal to 25 nm.

[0014] In yet another aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises a zincone.

[0015] In still another aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, wherein the first layer comprises ZnOx, A1OXand / or SiOxand the second layer comprises a metalcone.

[0016] In one aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating has a thickness of less than or equal to 100 nm and a water transmission of less than or equal to 10 g / m2-day.

[0017] In another aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating has a water transmission of less than or equal to 0.1 g / m2-day.

[0018] In still another aspect, a method is provided. According to some embodiments, the method comprises: depositing a barrier coating on a substrate using spatial atomic layer deposition (SALD), wherein depositing the barrier coating comprises oxidizing a zincone precursor on the substrate using an aliphatic polyol, an alkoxy-substituted ether, a dialdehyde, or a diketone.

[0019] In one aspect, a layered article is provided. According to some embodiments, the layered article comprises: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, wherein the barrier coating maintains (i) an oxygen transmission of less than or equal to 25 cc / m2-day or (ii) a water transmission of less than or equal to 25 g / m2-day and / or an oxygen transmission of less than or equal to 10 cm2 / m2-day after a 100 cycle Gelbo flex test.

[0020] Other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments of the disclosure when considered in conjunction with the accompanying figures. In cases where the present specification and a document incorporated by reference include conflicting and / or inconsistent disclosure, the present specification shall control.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Non-limiting embodiments of the present disclosure will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale unless otherwise indicated. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the disclosure shown where illustration is not necessary to allow those of ordinary skill in the art to understand the disclosure. In the figures:

[0023] FIG. 1A is a cross-sectional view of an exemplary film including a barrier coating disposed on a substrate, where the barrier coating includes bilayers with each bilayer having two layers of different materials, according to one set of embodiments.

[0024] FIG. IB is a cross-sectional view of an exemplary film including a barrier coating disposed on a substrate, where the barrier coating includes bilayers with each bilayer having two layers of different materials, according to one set of embodiments.

[0025] FIG. 2 is a diagram illustrating single-layer and multi-layer coatings with multiple functionalities on flexible material, according to one set of embodiments.

[0026] FIG. 3 is a diagram illustrating the spatial atomic layer deposition process to add a barrier coating on a flexible material, according to one set of embodiments.

[0027] FIGS. 4-7 are cross-sectional views of exemplary multilayers including a barrier coating, according to one set of embodiments. FIG. 8 is a diagram illustrating a spatial atomic layer deposition (SALD) process to deposit a barrier coating, according to one set of embodiments.

[0028] FIG. 9 is a diagram illustrating the components of the disclosed SALD apparatus, according to one set of embodiments.

[0029] FIGS. 10A-10B are diagrams illustrating the placement of SALD coaters on the same side or opposite sides of a flexible material in the disclosed apparatus and method, according to one set of embodiments.

[0030] FIG. 11 is a diagram illustrating the placement of other pieces of equipment between SALD coaters in the disclosed apparatus and method, according to one set of embodiments.

[0031] FIG. 12 is a diagram illustrating non-limiting stand-alone and drop-in embodiments of systems. According to some embodiments, the drop-in system can be integrated into a manufacturing line, according to one set of embodiments.

[0032] FIG. 13 is a diagram illustrating the disclosed method in which the number of coating layers and the thickness of each layer can be controlled by the specific arrangement of the apparatus and its operating parameters, according to one set of embodiments.

[0033] FIGS. 14A-14C are diagrams illustrating different embodiments, with respect to the direction of travel of the flexible material relative to the SALD coater(s), according to one set of embodiments.

[0034] FIG. 15 is a diagram illustrating an SALD apparatus to deposit a barrier coating.

[0035] FIG. 16A is a side-view diagram of an example apparatus with SALD heads in a radial compact adjacent spatial relationship, according to one set of embodiments.

[0036] FIG. 16B is a side-view diagram of an exemplary SALD head in greater detail, according to one set of embodiments.

[0037] FIG. 17 is a cross-section of a SALD head comprising a permeable material, according to one set of embodiments.

[0038] FIG. 18 is a cross-section of a segmented SALD head, according to one set of embodiments.

[0039] FIG. 19A is a cross-section of a SALD head, according to another embodiment. FIG. 19B is a cross-section of a segmented SALD head, according to a further embodiment.

[0040] FIG. 20 is a cross-section of a segmented SALD head, according to yet another embodiment.

[0041] FIG. 21 is a cross-section of the SALD head having a plurality of inserts, according to one set of embodiments.

[0042] FIG. 22 is a cross-section of the SALD head having a plurality of inserts, according to another embodiment.

[0043] FIG. 23 is a diagram of an apparatus to manufacture a film with a barrier coating using a spatial atomic layer deposition (SALD) head, according to one set of embodiments.

[0044] FIG. 24 is a diagram of another example apparatus to manufacture a film with a barrier coating using a SALD head, where the SALD head is positioned downstream of a dryer, according to one set of embodiments.

[0045] FIG. 25 is a diagram of another example apparatus to manufacture a film with a barrier coating using a SALD head, where the SALD head is positioned between a precoat subsystem and a top-coat subsystem, according to one set of embodiments.

[0046] FIG. 26 is a schematic diagram of an example SALD apparatus with thickness measurement devices, in which multiple measurement devices of different types are used, according to one set of embodiments.

[0047] FIG. 27 is an SEM micrograph of a non-limiting barrier coating after flex testing, according to one set of embodiments.

[0048] FIG. 28 is an SEM micrograph of a non-limiting barrier coating after flex testing, according to one set of embodiments.

[0049] FIG. 29A is a non-limiting schematic illustration of a close-proximity reactor head, according to one set of embodiments.

[0050] FIG. 29B is a non-limiting schematic illustration of single-layer AI2O3 and ZnO coatings on a flexible PLA packaging film, according to one set of embodiments.

[0051] FIG. 30A shows an SEM image of the surface of a bare polylactic acid (PLA) film, according to one set of embodiments. FIG. 30B shows an SEM image of the surface of an 8-stack nanolaminate, according to one set of embodiments.

[0052] FIG. 30C shows a cross-sectional transmission electron microscopy (TEM) image of a 4-stack nanolaminate coating on PLA, according to one set of embodiments.

[0053] FIG. 30D shows an energy-dispersive X-ray spectroscopy mapping of the image of a 4-stack nanolaminate coating on PLA, according to one set of embodiments.

[0054] FIG. 30E shows X-ray diffraction spectroscopy of bare PLA and various coatings, according to one set of embodiments.

[0055] FIG. 31 shows XRD of bare PLA after heating at different temperatures for 30 minutes, according to one set of embodiments.

[0056] FIGS. 32A-32C show WVTR measurements of as-deposited coatings on PLA, according to one set of embodiments.

[0057] FIG. 33A shows SEM of 96-nm ZnO on PLA, according to one set of embodiments.

[0058] FIG. 33B shows XRD of 96-nm ZnO on PLA and bare PLA, according to one set of embodiments.

[0059] FIG. 33C shows SEM of a 16-stack nanolaminate of AI2O3 and ZnO on PLA, according to one set of embodiments.

[0060] FIG. 33D shows SEM of a 8-stack nanolaminate of AI2O3 and ZnO on PLA, according to one set of embodiments.

[0061] FIG. 34A shows a schematic illustration of a bending measurement setup, according to one set of embodiments.

[0062] FIG. 34B shows water vapor transmission rates (WVTRs) after 0, 25 and 50 bends, according to one set of embodiments.

[0063] FIGS. 34C-34D show WVTRs for nanolaminates with different numbers of stacks after 25 bends (FIG. 34C) and 50 bends (FIG. 34D), according to one set of embodiments.

[0064] FIGS. 34E-34G show cross-sectional TEM of 4-stack, 8-stack, and 16-stack coatings were composed of continuous AI2O3 and ZnO layers, according to one set of embodiments. FIGS. 35A-35J show SEM images of films before and after various bending tests, according to one set of embodiments.

[0065] FIGS. 36A-36B show oxygen transmission rates (OTRs) measured at 90% relative humidity and 38 °C before and after bending: bare PLA (FIG. 36A), 8-stack nanolaminate on PEA (FIG. 36B), according to one set of embodiments.

[0066] FIG. 37A shows the OTR of bare PEA, according to one set of embodiments.

[0067] FIG. 37B shows the OTR of an 8-stack nanolaminate on PEA, according to one set of embodiments.

[0068] FIG. 37C shows the WVTR of bare PET, according to one set of embodiments.

[0069] FIG. 37D shows the WVTR of an 8-stack nanolaminate on PET, according to one set of embodiments.

[0070] FIG. 38A shows a schematic illustration of a Gelbo test setup, according to one set of embodiments.

[0071] FIG. 38B shows the WVTR of various articles after Gelbo testing, according to one set of embodiments.

[0072] FIG. 38C shows a schematic illustration of a lamination process, illustrating the lamination of the nanolaminate between two layers of PET, according to one set of embodiments.

[0073] FIG. 38D shows the WVTR of various articles after Gelbo testing, according to one set of embodiments.

[0074] FIGS. 39A-39B provide SEM images of an 8-stack nanolaminate on PET after Gelbo tests, according to one set of embodiments.

[0075] FIGS. 40A-40B show WVTRs of an 8-stack nanolaminate coating on PET after various Gelbo tests, according to one set of embodiments.

[0076] DETAILED DESCRIPTION

[0077] Various embodiments of multi-layered articles, packaging, and associated methods are generally provided. Multi-layered articles provide a number of advantages for the packaging and preservation of products. For example, in some embodiments, multilayered articles comprise barrier coatings that act as oxygen and / or water barriers, as well as substrate layers that provide mechanical support to a package. The demand for cheap, high quality packaging has increasingly driven the packaging industry towards unsustainable packaging. The industry is moving towards more sustainable solutions, which include but are not limited to, recyclable monolayer-structure plastic packaging, biodegradable materials, thinner plastic, more paper content, elimination of toxicity (e.g., chlorine, BPA), and removal of unsustainable materials (e.g., aluminum). “Sustainable packaging materials” are materials that are fully recyclable and / or compostable and / or biodegradable. However, these sustainable packaging solutions are lacking in barrier performance to protect the products. Barrier performance may include keeping packaged foods fresh by protecting them from external factors such as water, oxygen, light, aromas, and microbes.

[0078] Most conventional barrier coatings are not sufficient for use in sustainable packaging to protect products (e.g., food). For example, Poly vinylidene Dichloride (PVDC) is generally not recyclable, and toxic to the environment. For example, Ethylene Vinyl Alcohol (EVOH) is generally lacking in certain barrier properties. For example, plastic packaging with metal coatings (e.g., aluminum) is generally not recyclable because the metal layer is hard to be separated from the plastic at the recycling facility. In some cases, a metal detector at the recycling facility detects the metal and rejects it.

[0079] In some aspects, this disclosure relates to the use of alternative barrier-coating materials that provide superior barrier performance. Metal-oxide barrier coatings, such as aluminum oxide, silicon oxide, titanium dioxide, zinc oxide, and tin oxide can provide excellent barrier performance, even when they are ultra-thin (e.g., 50 nanometers). Advantageously, the relatively very thin nature of the barrier coatings (e.g., less than 100 nanometers) means that the concentration of metal in the packaging would be relatively very low. For example, for a 25 nm aluminum oxide barrier coating on a 100-micrometer packaging material, the concentration of aluminum in the packaging would be several orders of magnitude lower than that generally found in soil.

[0080] In addition to improved barrier properties, coatings are also desired on sustainable packaging materials to provide additional functionality, such as lightblocking properties, transparency for product- viewing, corrosion-resistance, antimicrobial properties, retortability, friction reduction, energy harvesting, sensing, display features, anti-counterfeiting, and tampering detection. Suitable coatings can accelerate the development of a circular economy for plastic and other packaging materials. The present disclosure, in some embodiments, relates to coatings with some or all of these properties.

[0081] Associated systems and methods are also provided. An apparatus and method for depositing functional coatings with different formulations on flexible materials is disclosed. Spatial atomic layer deposition produces dense coatings with few or no pinholes that are conformal to the underlying flexible substrate, which enhances the functional properties of the coatings. The apparatus and method can produce coatings that are single-layer or multi-layer and that have one or more functions. The apparatus and method operate in atmospheric conditions and can be used in a stand-alone or in-line manufacturing process. Spatial atomic layer deposition of metal-oxide barrier coatings on packaging materials is disclosed. The metal-oxide barrier coatings provide superior barrier properties to protect the products in the packaging, may perform additional functions, and may be sufficiently thin that they do not compromise the recyclability and / or compostability and / or biodegradability of sustainable packaging materials.

[0082] The present disclosure relates, in various aspects, to multilayered articles comprising barrier coatings applied to substrates. In particular, the present disclosure relates to new types of barrier coatings, e.g., of the type that may be fabricated by spatial atomic layer deposition (SALD, e.g., which may be atmospheric pressure spatial atomic layer deposition, AP-SALD). The barrier coatings provided herein may provide numerous advantages, including low cost, high quality, high resistance to the transport of water and oxygen, and high reusability, biodegradability, and / or compostability.

[0083] The term “layer” generally refers to an arrangement of material that, when the material is laid flat, has a thickness dimension, a depth dimension that is perpendicular to the thickness dimension, and a width dimension that is perpendicular to both the thickness dimension and the depth dimension, where the lengths of each of the depth dimension and the width dimension are at least 3 times the length of the thickness dimension. In some embodiments, the length of the depth dimension of the layer is at least 5 times, at least 10 times, at least 25 times, at least 50 times, at least 100 times, at least 500 times, or at least 1000 times the length of the thickness dimension of the layer. In some embodiments, the length of the width dimension of the layer is at least 5 times, at least 10 times, at least 25 times, at least 50 times, at least 100 times, at least 500 times, or at least 1000 times the length of the thickness dimension of the layer. The width and depth dimensions of a layer define its major surfaces.

[0084] FIG. 1A shows a non-limiting example of an article 100 comprising a barrier coating 102 disposed on a substrate 104. The article 100 may be used for packaging, such as food packaging (e.g., sealed bags or packages that contain food or ingredients, such as snacks, meat, cheese, etc.) , personal care products (e.g., creams, lotions, gels, soaps, etc.), pharmaceuticals, sterile medical products or instruments, agricultural products, and similar products that benefit from protection against degradation or contamination and / or that require a relatively long shelf life. According to some embodiments, the substrate provides mechanical strength to the article 100 and the barrier coating 102 provides a barrier against material (e.g., oxygen, water, gases, particles, contaminates, etc.) that may otherwise pass into or through the substrate 104.

[0085] The barrier coatings provided herein may provide a number of advantages for packaging. For example, in some embodiments the barrier coatings provide useful and unique combinations of physical and / or performance-related properties. Additionally, in some embodiments, the barrier coatings described herein may be produced using highly scalable and inexpensive techniques. For example, referring again to FIG. 1A, the barrier coating 102 may be deposited onto the substate 104 by spatial atomic layer deposition (SALD). SALD is compatible, in some embodiments, with manufacturing methods such as roll-to-roll manufacturing that are difficult to implement with other metal oxide barrier coating technologies. For example, SALD may be used to deposit multi-layered barrier coatings without requiring vacuum deposition, as discussed in greater detail below, and may therefore be well-adapted for producing pristine barrier coatings that have the advantages of multilayered barrier coatings detailed below, but that are comparatively easy to produce. Barrier coatings may be adjacent to a substrate (e.g., as described below). The barrier coating may be directly adjacent to the substrate (e.g., so that it is disposed directly on the substrate) or indirectly adjacent (e.g., such that one or more layers separates the barrier coating from the substrate).

[0086] The embodiments described herein relate, in some embodiments, to an ultra-thin functional coating comprised of one or more layers on a flexible substrate material, and the apparatus and method for applying the coating. More specifically, the coating may be an elemental or compound material that performs one or more functions, either on its own or in combination with one or more other components. Functions may include, but are not limited to, water-barrier properties, oxygen-barrier properties, grease-barrier properties, aroma-barrier properties, light-blocking, corrosion resistance, transparency for product viewing, corrosion resistance, antimicrobial properties, friction reduction, energy harvesting, sensing, display features, anti-counterfeiting, and tampering detection. The ultra-thin functional coating can be formed during the manufacture of the flexible material or in later manufacturing stages by use of spatial atomic layer deposition techniques.

[0087] Ultra-thin functional coatings may be used on flexible materials for a wide range of packaging applications. Examples include, but are not limited to, coatings that protect the products contained in the packaging (e.g., foodstuffs) from external factors, coatings that provide antimicrobial properties (e.g., packaging for healthcare products), and coatings that allow the integration of energy-harvesting, sensing, and display properties into smart packaging materials.

[0088] Barrier coatings may be used on flexible packaging materials to protect products (e.g., foodstuffs) from external factors that include, but are not limited to, water vapor, water, oxygen, light, aromas, grease, and foreign matter. Protection from these external factors is necessary to extend the shelf-life of the product and ensure it is safe for use or consumption. Examples of current barrier coatings include Polyvinylidene Dichloride (PVDC), Ethylene Vinyl Alcohol (EVOH), and metallization (metal or metal-oxide coatings). Examples of metal and metal-oxide barrier coatings include aluminum, aluminum oxide, and silicon oxide.

[0089] In one embodiment of the disclosed coating, the coating is comprised of a single layer of material, such as aluminum oxide, silicon oxide, or tin oxide, but not limited to the stated. In another embodiment of the disclosed coating, the coating may comprise several layers of different materials, where the thickness of each layer can be controlled by a disclosed method (e.g., 10 nanometers (nm) of aluminum oxide - 5 nm of zinc oxide - 10 nm of aluminum oxide - 5 nm of zinc oxide - 10 nm of aluminum oxide - 10 nm of cuprous oxide). Other examples of barrier coatings comprising multiple layers are described in greater detail below; it should, of course, be understood that the preceding layers and thicknesses are exemplary and non-limiting. The different layers of the coating may provide multiple functions that include, but are not limited to, enhanced barrier properties, enhanced mechanical properties, light blocking, and antimicrobial properties.

[0090] The barrier coating may include a plurality of layers. In some embodiments, for example, a barrier coating comprises a first layer and a second layer, the first layer alternating with the second layer. For example, as shown in FIG. 1A, barrier coating 102 includes a stack of bilayers 106. Each of bilayers 106 comprises a first layer 108 and a second layer 110. Any suitable number of bilayers 106 may be used. The first layer 106 and the second layer 108 may be adjacent. For example, they may be directly adjacent. As used herein, when a layer is referred to as being “on” or “adjacent” another layer, it can be directly on or adjacent the layer, or an intervening layer or material also may be present. A layer that is “directly on”, “directly adjacent” or “in contact with” another layer means that no intervening layer or material is present.

[0091] The layers of a barrier coating may have any of a variety of appropriate orders and / or configurations. For example, in some embodiments, a barrier coating comprises a bilayer where the first layer (e.g., comprising an oxide) of the barrier coating is between a second layer (e.g., comprising a metalcone) of the bilayer and the substrate. In some embodiments, a barrier coating comprises a barrier coating comprises a bilayer wherein the second layer (e.g., comprising the metalcone) is disposed between the first layer (e.g., comprising the oxide) and the substrate. In some embodiments, a first layer of the barrier coating (e.g., comprising an oxide) is directly adjacent to the substrate. In some embodiments, a second layer (e.g., comprising a metalcone) is directly adjacent to the substrate. Other arrangements (e.g., comprising more complicated layering arrangements) are also possible, as the disclosure is not so limited.

[0092] In some embodiments, a barrier coating comprises greater than or equal to 1 first layer, greater than or equal to 2 first layers, greater than or equal to 4 first layers, greater than or equal to 6 first layers, greater than or equal to 8 first layers, greater than or equal to 10 first layers, greater than or equal to 12 first layers, greater than or equal to 14 first layers, greater than or equal to 16 first layers, greater than or equal to 18 first layers, greater than or equal to 20 first layers, greater than or equal to 22 first layers, greater than or equal to 24 first layers, greater than or equal to 26 first layers, greater than or equal to 28 first layers, greater than or equal to 30 first layers, or greater than or equal to 40 first layers. In some embodiments, a barrier coating comprises less than or equal to 50 first layers, less than or equal to 40 first layers, less than or equal to 30 first layers, less than or equal to 28 first layers, less than or equal to 26 first layers, less than or equal to 24 first layers, less than or equal to 22 first layers, less than or equal to 20 first layers, less than or equal to 18 first layers, less than or equal to 16 first layers, less than or equal to 14 first layers, less than or equal to 12 first layers, less than or equal to 10 first layers, less than or equal to 8 first layers, less than or equal to 6 first layers, or less than or equal to 4 first layers. Combinations of these ranges are also possible (e.g., greater than or equal to 1 first layers and less than or equal to 50 layers, greater than or equal to 2 first layers and less than or equal to 30 first layers, or greater than or equal to 2 first layers and less than or equal to 12 first layers). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0093] In some embodiments, a barrier coating comprises greater than or equal to 1 second layer, greater than or equal to 2 second layers, greater than or equal to 4 second layers, greater than or equal to 6 second layers, greater than or equal to 8 second layers, greater than or equal to 10 second layers, greater than or equal to 12 second layers, greater than or equal to 14 second layers, greater than or equal to 16 second layers, greater than or equal to 18 second layers, greater than or equal to 20 second layers, greater than or equal to 22 second layers, greater than or equal to 24 second layers, greater than or equal to 26 second layers, greater than or equal to 28 second layers, greater than or equal to 30 second layers, or greater than or equal to 40 second layers. In some embodiments, a barrier coating comprises less than or equal to 50 second layers, less than or equal to 40 second layers, less than or equal to 30 second layers, less than or equal to 28 second layers, less than or equal to 26 second layers, less than or equal to 24 second layers, less than or equal to 22 second layers, less than or equal to 20 second layers, less than or equal to 18 second layers, less than or equal to 16 second layers, less than or equal to 14 second layers, less than or equal to 12 second layers, less than or equal to 10 second layers, less than or equal to 8 second layers, less than or equal to 6 second layers, or less than or equal to 4 second layers. Combinations of these ranges are also possible (e.g., greater than or equal to 1 second layers and less than or equal to 50 layers, greater than or equal to 2 second layers and less than or equal to 30 second layers, or greater than or equal to 2 second layers and less than or equal to 12 second layers). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0094] Combinations of the forgoing ranges are also possible. For example, in some embodiments the barrier coating comprises greater than or equal to 2 layers of the first layer and greater than or equal to 2 layers of the second layer. In various examples, between 2 and 12 bilayers may be stacked to form the barrier coating 102.

[0095] Each bilayer includes two layers 108, 110 of different materials. The term “bilayer” and similar terms used herein are open-ended unless otherwise specified. In this example, two layers means two or more layers, and a bilayer may be a tri-layer, etc.

[0096] A particular bilayer 106 design may be repeated to form a stack of bilayers 106 that forms the barrier coating 102. Repetition of bilayers 106 provides robustness in that a particular layer 108 or 110 may crack or exhibit a flaw without compromising the integrity of the barrier coating 102 as a whole. Multiple layers of material 108, 110 may experience localized failure while still providing an effective coating overall.

[0097] Layers of a barrier coating may have any of a variety of suitable thicknesses, depending on the embodiment. In some embodiments, layers of a barrier coating (e.g., first layers, second layers) have an average thickness of greater than or equal to 1 nm, greater than or equal to 2 nm, greater than or equal to 3 nm, greater than or equal to 4 nm, greater than or equal to 5 nm, greater than or equal to 8 nm, greater than or equal to 10 nm, greater than or equal to 12 nm, greater than or equal to 15 nm, greater than or equal to 18 nm, greater than or equal to 20 nm, greater than or equal to 22 nm, greater than or equal to 25 nm, greater than or equal to 28 nm, greater than or equal to 30 nm, greater than or equal to 35 nm, greater than or equal to 40 nm, or greater than or equal to 45 nm. In some embodiments, layers of a barrier coating have an average thickness of less than or equal to 50 nm, less than or equal to 45 nm, less than or equal to 40 nm, less than or equal to 35 nm, less than or equal to 30 nm, less than or equal to 28 nm, less than or equal to 25 nm, less than or equal to 22 nm, less than or equal to 20 nm, less than or equal to 18 nm, less than or equal to 15 nm, less than or equal to 12 nm, less than or equal to 10 nm, less than or equal to 8 nm, less than or equal to 5 nm, less than or equal to 4 nm, less than or equal to 3 nm, or less than or equal to 2 nm. Combinations of these ranges are also possible (e.g., greater than or equal to 1 nm and less than or equal to 50 nm, greater than or equal to 3 nm and less than or equal to 30 nm, or greater than or equal to 4 nm and less than or equal to 12 nm). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited. In various examples, each bilayer 106 may have a thickness of between about 3 nanometers and about 30 nanometers. More specifically, each bilayer 106 may have a thickness of between about 4 nanometers and about 12 nanometers.

[0098] According to some embodiments, the barrier coating comprises an initiation layer on one side of the barrier coating. The nucleation layer may be the first layer formed on a substrate or primer layer, depending on the embodiment. In some embodiments, it is advantageous for the initiation layer to be thicker than the other layers of the barrier coating. For example, the initiation layer may be at least 5%, 10%, 50%, 100%, 125%, or 150% thicker than other layers of the barrier coating with similar composition, depending on the embodiment. In the context of the present disclosure it has been recognized that use of a thicker initiation layer may result in higher quality barrier coatings, depending on the embodiment. For example, without wishing to be bound by any particular theory, the use of a thicker initiation layer may result in a more uniform barrier coating thickness and / or may provide a more uniform substrate for formation of another layer of the barrier coating.

[0099] A barrier coating may have any of a variety of suitable thicknesses. In some embodiments, a barrier coating has an average thickness of greater than or equal to 10 nm, greater than or equal to 20 nm, greater than or equal to 30 nm, greater than or equal to 40 nm, greater than or equal to 50 nm, greater than or equal to 60 nm, greater than or equal to 70 nm, greater than or equal to 80 nm, greater than or equal to 90 nm, greater than or equal to 100 nm, greater than or equal to 110 nm, greater than or equal to 120 nm, greater than or equal to 130 nm, greater than or equal to 140 nm, greater than or equal to 150 nm, greater than or equal to 160 nm, greater than or equal to 170 nm, greater than or equal to 180 nm, or greater than or equal to 190 nm. In some embodiments, a barrier coating has an average thickness of less than or equal to 200 nm, less than or equal to 190 nm, less than or equal to 180 nm, less than or equal to 170 nm, less than or equal to 160 nm, less than or equal to 150 nm, less than or equal to 140 nm, less than or equal to 130 nm, less than or equal to 120 nm, less than or equal to 110 nm, less than or equal to 100 nm, less than or equal to 90 nm, less than or equal to 80 nm, less than or equal to 70 nm, less than or equal to 60 nm, less than or equal to 50 nm, less than or equal to 40 nm, less than or equal to 30 nm, or less than or equal to 20 nm. Combinations of these ranges are also possible (e.g., greater than or equal to 10 nm and less than or equal to 200 nm, greater than or equal to 10 nm and less than or equal to 100 nm, or greater than or equal to 20 nm and less than or equal to 100 nm). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited. In various examples, the barrier coating 102 may have a total thickness of between about 20 nanometers and about 100 nanometers. More specifically, the barrier coating 102 may have a total thickness of between about 30 nanometers and about 90 nanometers.

[0100] One advantage of barrier coatings described herein is that they may have a relatively uniform thickness, even when a comparatively rough substrate is used. In some embodiments, a barrier coating has a thickness that varies by less than or equal to 100%, less than or equal to 90%, less than or equal to 80%, less than or equal to 70%, less than or equal to 60%, less than or equal to 50%, less than or equal to 40%, less than or equal to 30%, or less than or equal to 20% of the average thickness of the barrier coating. In some embodiments, a barrier coating has a thickness that varies by greater than or equal to 10%, greater than or equal to 20%, greater than or equal to 30%, greater than or equal to 40%, greater than or equal to 50%, greater than or equal to 60%, greater than or equal to 70%, greater than or equal to 80%, or greater than or equal to 90% of the average thickness of the barrier coating. Combinations of these ranges are also possible (e.g., greater than or equal to 10% and less than or equal to 100%, greater than or equal to 20% and less than or equal to 100%, or greater than or equal to 20% and less than or equal to 80%). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited. The bilayers 106 generally have the same layers of materials 108, 110, though the thicknesses of the materials 108, 110 may differ among the bilayers 106. For example, the layer of material in contact with the substrate 104 may be thicker than other layers of material that are not in contact with the substrate 104. Such a thicker layer of material may help even out surface roughness of the substrate 104 to promote barrier coating effectiveness.

[0101] The barrier coating may include silicone, an oxide, a metal oxide, an alkoxide, a metalcone (e.g., an “alucone” or “zincone”), oxynitride or similar material. For example, each layer of material 108, 110 may include silicone, an oxide, a metal oxide, an alkoxide, a metalcone (e.g., an “alucone” or “zincone”) or similar material. The barrier coating may include a layer of silicon oxide, magnesium oxide, aluminum oxide and / or a layer of zinc oxide. For example, a bilayer 106 may include a layer 108 comprising aluminum oxide (e.g., A1OX) or a precursor thereof (e.g., A1(CH3)3). In some embodiments, a bilayer comprises a layer 110 of zinc oxide (e.g., ZnOx). Aluminum oxide may act as the main gas barrier material. Zinc oxide may act as a structural layer and may provide other benefits, such as ultraviolet (UV) light blocking. In various examples, the barrier coating is configured so that an aluminum oxide layer contacts the substrate. In other examples, the barrier coating is configured so that a zinc oxide layer contacts the substrate, which may improve barrier performance against moisture. The substrate-facing surface layer (which may be an initiation layer, in some embodiments) may be thicker than the other layers. In some embodiments, the barrier coating comprises one or more materials that are safe for food-contact. For example, the barrier coating itself is food-contact safe, in some embodiments.

[0102] According to some embodiments, advantages have been recognized to the use of a barrier coating comprising a metalcone. For example, in some embodiments the metalcone can contribute flexibility and / or crack resistance to the barrier coating. The metalcone may be introduced by any of a variety of suitable reactions. For example, in some embodiments the metalcone is formed by oxidizing a precursor (e.g., a precursor comprising silicon, aluminum, or zinc) using an organic linker (e.g., an oxidant). For example, the precursor may be trimethylaluminum or diethylzinc. The organic linker may, in some embodiments, be an aliphatic polyol (e.g., a glycol). For example, in some embodiments, the precursor is ethylene glycol, propylene glycol, or butanediol. In some embodiments the aliphatic polyol is a triol (e.g., glycerol). In some embodiments, the organic linker is a non-aliphatic polyol (e.g., an aromatic polyol such as hydroquinone). In some embodiments the organic linker is an alkoxy-substituted ether (e.g., dimethoxy ethane), a dialdehyde, or a diketone. Without wishing to be bound by any particular theory, the metalcone may be comparatively flexible (e.g., relative to a comparable metal oxide) as a result of flexibility provided by the organic linker, resulting in improved toughness. Without wishing to be bound by any theory, the metalcone may be capable of absorbing water and / or may be capable of performing as a barrier to water or oxygen permeation.

[0103] The layers of a multi-layered barrier coating may each, independently, include one or more of the materials recited above, and layers with different compositions may be arranged in any of a variety of suitable orders, as the disclosure is not so limited. For example, a barrier coating can comprise a mixture of inorganic (e.g., oxide) layers and organic (e.g., metalcone) layers, optionally in the form of bilayers. For example, in some embodiments, the barrier comprises at least four consecutive layers, wherein the at least four consecutive layers comprising predominantly the following materials, respectively: aluminum oxide - alucone - aluminum oxide - alucone. In some embodiments, the barrier comprises at least four consecutive layers, wherein the at least four consecutive layers comprising predominantly the following materials, respectively: aluminum oxide - zincone - aluminum oxide - zincone. In some embodiments, the barrier comprises at least four consecutive layers, wherein the at least four consecutive layers comprising predominantly the following materials, respectively: aluminum oxide - silicone - aluminum oxide - silicone. In some embodiments, the barrier comprises at least four consecutive layers, wherein the at least four consecutive layers comprising predominantly the following materials, respectively: silicon oxide - alucone - silicon oxide - alucone. Any of a variety of other layer arrangements are also possible, as the disclosure is not so limited.

[0104] In some embodiments, other materials, such as tin oxide, silicon oxide, magnesium oxide, and titanium dioxide, may be used. Generally, a barrier coating may include any of a variety of suitable molar ratios of oxides. In some embodiments, a barrier coating comprises a molar ratio of a first oxide (e.g., A1OX) to a second oxide (e.g., ZnOy, MgO, or SiOz) of greater than or equal to 1:2, greater than or equal to 1:1, greater than or equal to 3:2, or greater than or equal to 2:1. In some embodiments, a barrier coating comprises a molar ratio of a first oxide to a second oxide of less than or equal to 5:2, less than or equal to 2:1, less than or equal to 3:2, or less than or equal to 1:1. Combinations of these ranges are also possible (e.g., or greater than or equal to 1:2 and less than or equal to 5:2). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0105] In some embodiments, a barrier coating comprises a molar ratio of a first metal in an oxide (e.g., Al in a first, AlOx layer) to a second metal in a metalcone (e.g., Zn in a second, zincone layer) of greater than or equal to 1:3, greater than or equal to 1:2, greater than or equal to 1:1, greater than or equal to 3:2, greater than or equal to 2:1, greater than or equal to 5:2. In some embodiments, a barrier coating comprises a molar ratio of a first metal to a second metal of less than or equal to 3:1 less than or equal to 5:2, less than or equal to 2:1, less than or equal to 3:2, or less than or equal to 1:1. Combinations of these ranges are also possible (e.g., greater than or equal to 1:3 and less than or equal to 3:1, or greater than or equal to 1:2 and less than or equal to 5:2). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0106] As discussed above, any of a variety of suitable metalcones may be used. However, according to one set of embodiments, advantages have been identified recognized to the use of zincone in barrier coatings. For example, as discussed in the Examples below, zincone has been identified as contributing to particularly tough, high performance barrier coatings, e.g., when used as a first layer of a barrier coating in combination with a second layer of a barrier coating comprising an oxide such as SiOx or AlOx.

[0107] In at least one aspect, deposition of a barrier coating (e.g., an ultra-thin metal- oxide coating) on a flexible material such as polyethylene, polypropylene, polylactic acid, paperboard or kraft paper, is provided. The coating provides barrier properties to protect the products that are packaged within the flexible material or materials. Barrier in this context may mean water-vapor barrier, oxygen barrier, aroma barrier, grease barrier, or aqueous liquid barrier, but is not limited to the stated. These barrier properties prevent extemal factors from entering the package to keep the products fresh and may extend the shelf life of products such as food.

[0108] A barrier coating provided herein may be configured to limit oxygen transmission (e.g., by maintaining a low oxygen transmission rate, OTR). In some embodiments, a barrier coating has an oxygen transmission rate of less than or equal to 10 cc / m2-day, less than or equal to 9 cc / m2-day, less than or equal to 8 cc / m2-day, less than or equal to 7 cc / m2-day, less than or equal to 6 cc / m2-day, less than or equal to 5 cc / m2-day, less than or equal to 4 cc / m2-day, less than or equal to 3 cc / m2-day, less than or equal to 2 cc / m2- day, less than or equal to 1 cc / m2-day, less than or equal to 0.5 cc / m2-day, less than or equal to 0.1 cc / m2-day, less than or equal to 0.05 cc / m2-day, or less than or equal to 0.01 cc / m2-day. In some embodiments, a barrier coating has an oxygen transmission rate of greater than or equal to greater than or equal to 0.001 cc / m2-day, greater than or equal to 0.01 cc / m2-day, greater than or equal to 0.05 cc / m2-day, greater than or equal to 0.1 cc / m2-day, greater than or equal to 0.5 cc / m2-day, greater than or equal to 1 cc / m2-day, greater than or equal to 2 cc / m2-day, greater than or equal to 3 cc / m2-day, greater than or equal to 4 cc / m2-day, greater than or equal to 5 cc / m2-day, greater than or equal to 6 cc / m2-day, greater than or equal to 7 cc / m2-day, greater than or equal to 8 cc / m2-day, or greater than or equal to 9 cc / m2-day. Combinations of these ranges are also possible (e.g., greater than or equal to 0.001 cc / m2-day and less than or equal to 10 cc / m2-day, greater than or equal to 0.01 cc / m2-day and less than or equal to 10 cc / m2-day or greater than or equal to 1 cc / m2-day and less than or equal to 10 cc / m2-day). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited. According to some embodiments, the foregoing OTR values are determined at 23 °C and 50% relative humidity. In some embodiments, the foregoing OTR values are determined at 23 °C and 50% relative humidity. In some embodiments, the foregoing OTR values are determined at 23 °C and 80% relative humidity. In some embodiments, the foregoing OTR values are determined at 38 °C and 80% relative humidity. According to some embodiments, the foregoing OTR values are determined at 38 °C and 90% relative humidity.

[0109] A barrier coating provided herein may be configured to limit water transmission (e.g., by maintaining a low water vapor transmission rate, WVTR). In some embodiments, a barrier coating has a water transmission of less than or equal to 25 g / m2- day, less than or equal to 23 g / m2-day, less than or equal to 21 g / m2-day, less than or equal to 19 g / m2-day, less than or equal to 17 g / m2-day, less than or equal to 15 g / m2-day, less than or equal to 13 g / m2-day, less than or equal to 11 g / m2-day, less than or equal to 9 g / m2-day, less than or equal to 7 g / m2-day, less than or equal to 5 g / m2-day, less than or equal to 3 g / m2-day, less than or equal to 1 g / m2-day, less than or equal to 0.5 g / m2-day, less than or equal to 0.1 g / m2-day, less than or equal to 0.05 g / m2-day, or less than or equal to 0.025 g / m2-day. In some embodiments, a barrier coating has a water transmission of greater than or equal to 0.001 g / m2-day, greater than or equal to 0.025 g / m2-day, greater than or equal to 0.005 g / m2-day, greater than or equal to 0.01 g / m2-day, greater than or equal to 0.05 g / m2-day, greater than or equal to 0.1 g / m2-day, greater than or equal to 0.5 g / m2-day, greater than or equal to 1 g / m2-day, greater than or equal to 3 g / m2-day, greater than or equal to 5 g / m2-day, greater than or equal to 7 g / m2-day, greater than or equal to 9 g / m2-day, greater than or equal to 11 g / m2-day, greater than or equal to 13 g / m2-day, greater than or equal to 15 g / m2-day, greater than or equal to 17 g / m2-day, greater than or equal to 19 g / m2-day, greater than or equal to 21 g / m2-day, or greater than or equal to 23 g / m2-day. Combinations of these ranges are also possible (e.g., greater than or equal to 0.01 g / m2-day and less than or equal to 25 g / m2-day, greater than or equal to 0.5 g / m2-day and less than or equal to 25 g / m2-day or greater than or equal to 1 g / m2-day and less than or equal to 25 g / m2-day). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited. According to some embodiments, the foregoing WVTR values are determined at 23 °C and 50% relative humidity. In some embodiments, the foregoing WVTR values are determined at 23 °C and 50% relative humidity. In some embodiments, the foregoing WVTR values are determined at 23 °C and 80% relative humidity. In some embodiments, the foregoing WVTR values are determined at 38 °C and 80% relative humidity. According to some embodiments, the foregoing WVTR values are determined at 38 °C and 90% relative humidity.

[0110] The articles provided herein may have a variety of suitable properties depending, e.g., on the chosen combination of the barrier coating, the primer layer, and / or the substrate of the article. In some embodiments, an article provided herein has a relatively low substrate hygroexpansion (e.g., the article may comprise a substrate that, in isolation would exhibit substantial hygroexpansion but that because of the barrier layer and / or primer layers deposited thereon exhibits relatively low hygroexpansion). For example, according to some embodiments, an article (e.g., an article with a substrate comprising a web of cellulose fibers), maintained for a duration of at least 24 hours at 38°C at 90% relative humidity, exhibits a substrate hygroexpansion of less than or equal to 0.500%, less than or equal to 0.475%, less than or equal to 0.450%, less than or equal to 0.425%, less than or equal to 0.400%, less than or equal to 0.375%, less than or equal to 0.350%, less than or equal to 0.325%, less than or equal to 0.300%, less than or equal to 0.275%, less than or equal to 0.250%, or less than or equal to 0.225%. In some embodiments, an article, maintained for a duration of at least 24 hours at 38°C at 90% relative humidity, exhibits a substrate hygroexpansion of greater than or equal to 0.200%, greater than or equal to 0.225%, greater than or equal to 0.250%, greater than or equal to 0.275%, greater than or equal to 0.300%, greater than or equal to 0.325%, greater than or equal to 0.350%, greater than or equal to 0.375%, greater than or equal to 0.400%, greater than or equal to 0.425%, greater than or equal to 0.450%, or greater than or equal to 0.475%. Combinations of these ranges are also possible (e.g., greater than or equal to 0.200% and less than or equal to 0.500%, or greater than or equal to 0.325% and less than or equal to 0.500%). Other values are also possible, as the disclosure is not so limited.

[0111] The barrier coatings provided herein may be tough enough to maintain a relatively low water transmission and / or oxygen transmission (e.g., within one of the foregoing ranges) even after flex durability testing. For example, in some embodiments, a barrier coating provided herein may be configured to maintain a water transmission or oxygen transmission within one of the foregoing ranges, even after cycling in a Gelbo flex durability test conducted according the standard set forth by ASTM F392. Accordingly, a layered article provided herein may be configured to maintain a water transmission or oxygen transmission within a foregoing range after being subjected to a Gelbo test for greater than or equal to 1 cycle, greater than or equal to 20 cycles, greater than or equal to 40 cycles, greater than or equal to 50 cycles, greater than or equal to 60 cycles, greater than or equal to 80 cycles, greater than or equal to 100 cycles, greater than or equal to 150 cycles, greater than or equal to 200 cycles, greater than or equal to 250 cycles, greater than or equal to 300 cycles, greater than or equal to 350 cycles, greater than or equal to 400 cycles, or greater than or equal to 450 cycles. In some embodiments, a layered article provided herein may be configured to maintain a water transmission or oxygen transmission within a foregoing range after being subjected to a Gelbo test for less than or equal to 500 cycles, less than or equal to 450 cycles, less than or equal to 400 cycles, less than or equal to 350 cycles, less than or equal to 300 cycles, less than or equal to 250 cycles, less than or equal to 200 cycles, less than or equal to 150 cycles, less than or equal to 100 cycles, less than or equal to 80 cycles, less than or equal to 60 cycles, less than or equal to 50 cycles, less than or equal to 40 cycles, or less. Combinations of these ranges with the foregoing ranges are also possible (e.g., in some embodiments a layered article is configured to maintain a water transmission of less than or equal to 25 g / m2-day and / or an oxygen transmission of less than or equal to 10 cm2 / m2-day after a 1 cycle Gelbo flex test, in some embodiments a layered article is configured to maintain a water transmission of less than or equal to 10 g / m2-day after a 300 cycle Gelbo flex test, etc.). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0112] The barrier coatings provided herein may be tough enough to maintain a relatively low water transmission and / or oxygen transmission (e.g., within one of the foregoing ranges) even after flex resistance testing. For example, in some embodiments, a barrier coating provided herein may be configured to maintain a water transmission or oxygen transmission within one of the foregoing ranges, even after repeated bending according to the flex resistance test described in Example 2 (whereby a 26 cm x 4 cm article is suspended from a 7 cm-diameter roller, a 1-kg weight is attached to the films to apply uniform tension, and the roller is cycled by rotating it 360° counterclockwise before returning it to its starting position, hereinafter a “bending cycle”).

[0113] Accordingly, a layered article provided herein may be configured to maintain a water transmission or oxygen transmission within a foregoing range after being subjected to greater than or equal to 1 bending cycles, greater than or equal to 5 bending cycles, greater than or equal to 10 bending cycles, greater than or equal to 15 bending cycles, greater than or equal to 20 bending cycles, greater than or equal to 25 bending cycles, greater than or equal to 30 bending cycles, greater than or equal to 35 bending cycles, greater than or equal to 40 bending cycles, or greater than or equal to 45 bending cycles. In some embodiments, a layered article provided herein may be configured to maintain a water transmission or oxygen transmission within a foregoing range after being subjected to less than or equal to 100 bending cycles, less than or equal to 75 bending cycles, less than or equal to 50 bending cycles, less than or equal to 45 bending cycles, less than or equal to 40 bending cycles, less than or equal to 35 bending cycles, less than or equal to 30 bending cycles, less than or equal to 25 bending cycles, less than or equal to 20 bending cycles, less than or equal to 15 bending cycles, or less than or equal to 10 bending cycles. Combinations of these ranges with the foregoing ranges are also possible (e.g., in some embodiments a layered article is configured to maintain a water transmission of less than or equal to 25 g / m2-day and / or an oxygen transmission of less than or equal to 10 cm2 / m2-day after 100 bending cycles, in some embodiments a layered article is configured to maintain a water transmission of less than or equal to 10 g / m2-day after a 50 bending cycles, etc.). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0114] The coating material may be a metal oxide, but other compositions such as metals, metal nitrides, metal sulfides, multi-component alloys, and doped materials may also be used. The functional coating may have a thickness on the order of 10 to 100 nanometers but is not limited to the stated thicknesses. In the disclosed apparatus and method, according to one set of embodiments, the number of gas channels in one or more SALD coaters, the number of precursor and / or reactant chemicals delivered by the gas channels, and the sequence in which the flexible material is exposed to the gas channels can be varied, allowing manufacture of single-layer and multi-layer thin-film coatings, as illustrated in FIG. 2. A single-layer functional coating composed of one type of coating material (e.g., aluminum oxide) of variable thickness is disclosed. A multi-layer (or nanolaminate) functional coating is also disclosed, according to one set of embodiments. The multi-layer functional coating may comprise two or more coating materials (e.g., aluminum oxide, zinc oxide, tin oxide, silicon oxide, titanium dioxide). Alternatively, the multi-layer coating may be comprised one coating material (e.g., aluminum oxide), where the properties of the material are varied between the different layers using techniques such as, but not limited to, doping some of the layers with small quantities of additional elements, varying the deposition conditions used for some of the layers (e.g., deposition temperature), varying the ratio of precursor and reactant chemicals used, and varying the type of precursor or reactant. The multi-layer functional coatings may have any number of layers and these layers may be deposited in any sequence, including repeating patterns (e.g., repeating aluminum oxide-zinc oxide-tin oxide layers). Furthermore, each layer within the multi-layer coating can have any thickness on the order of tens of nanometers or less.

[0115] The disclosed single-layer coatings may have multiple functions, depending on the coating material and thin-film coating properties (e.g., thickness and roughness). Functions include, but are not limited to, water-barrier properties, oxygen-barrier properties, grease-barrier properties, aroma-barrier properties, light-blocking, corrosion resistance, transparency for product-viewing, antimicrobial properties, friction reduction, energy harvesting, sensing, display features, anticounterfeiting, and tampering detection. Examples of single-layer functional coatings are illustrated in FIG. 2. One embodiment is an aluminum-oxide coating with water-vapor-barrier and / or oxygen-barrier functions. Another embodiment is a zinc-oxide coating with ultraviolet-light-blocking and / or antimicrobial functions. Another embodiment is a silicon-oxide coating with water- vapor-barrier, oxygen barrier, and corrosion-resistance functions.

[0116] The disclosed multi-layer barrier coatings may have multiple functions, which may include, but are not limited to, water-barrier properties, oxygen-barrier properties, grease-barrier properties, aroma barrier properties, light-blocking, corrosion resistance, transparency for product- viewing, corrosion resistance, antimicrobial properties, friction reduction, energy harvesting, sensing, display features, anti-counterfeiting, and tampering detection. Examples of multi-layer functional coatings are illustrated in FIG. 2. One embodiment is an aluminum oxide-zinc oxide stacked coating with water-vapor barrier and / or oxygen-barrier and / or ultraviolet-light-blocking and / or antimicrobial functions. Another embodiment is an aluminum oxide-zinc oxide- silicon oxide stacked coating with water-vapor-barrier and / or oxygen-barrier and / or ultraviolet-light-blocking and / or antimicrobial and / or corrosion-resistance functions.

[0117] According to further embodiments of the disclosure, the disclosed functional coatings may be combined with other functional layers or materials deposited using other - 1 - techniques. For example, luminescent films, metal circuitry or nanoparticles deposited by techniques such as inkjet printing, screen printing, and gravure coating may be placed on top of the disclosed functional coatings and / or underneath the disclosed functional coatings on the flexible packaging material and / or embedded within the disclosed functional coatings.

[0118] Inline surface treatment may help remove dust and particles to improve surface cleanliness and prevent pinhole formation. The barrier coating may conformally coat the surface and encapsulate any dust particles and thus surface treatment may be used but is not expected to be required in many cases.

[0119] The barrier coating may be deposited using spatial atomic layer deposition (SALD). FIG. 3 is a diagram illustrating one embodiment, whereby the disclosed apparatus and method are used to add metal-oxide barrier coatings onto flexible packaging materials. As shown in FIG. 3, an initially permeable material may be coated using SALD to introduce a barrier coating that reduces the water and oxygen transmission (e.g., reducing water transmission to below 1 g / m2-day and reducing oxygen transmission to below 1 cm3 / m2-day). FIG. 3(a) shows an uncoated flexible packaging material that inherently has poor barrier performance. The barrier performance here could be characterized by the water-vapor-transmission rate and oxygen transmission rate, which measure how much moisture and oxygen pass through the flexible material per square meter of area per day. However, other barriers may also include, but are not limited to, grease, light and aroma barriers. FIG. 3(b) show the flexible packaging material passing next to a SALD coater to add the barrier coating. FIG. 3(c) shows the SALD coating process of this disclosure. When the flexible packaging material passes by the SALD coater, it gets exposed to different chemicals, e.g., those in gaseous form. Approximately one atomic layer of the coating is formed by sequential reactions of a precursor chemical (e.g. trimethylaluminum, Ah(CH3)6, for aluminum oxide) and reactant chemical (e.g., an oxidant such as H2O) on the surface of the packaging material. Different precursor and reactant chemicals can be employed for different coating materials and to control the properties of the barrier coating. The precursor(s) and reactant(s) may be delivered by a carrier gas, such as nitrogen, and are delivered out of parallel channels in the coater that extend across the surface of the flexible material. It should, of course, be understood that these methods, reagents, and barrier coatings are merely representative and that any of a variety of methods, reagents, and barrier coatings may be used, depending on the embodiment.

[0120] An inert gas (e.g., nitrogen) is also delivered from dedicated coater channels to the surface of the flexible packaging material, according to one set of embodiments. Without wishing to be bound by any particular theory, the inert gas may act as a gas curtain to spatially separate the precursor and reactant chemicals and prevent them from mixing and reacting before reaching the surface of the packaging material. Exhaust channels may also be included in the coater to remove gases from the space between the surface of the coater and surface of the flexible material. Spatial separation of the precursor and reactant chemicals allows sequential chemical reactions on the surface of the flexible material so that the coating can be added approximately one atomic layer at a time, providing precise control over the coating thickness. FIG. 3(d) illustrates the coated flexible packaging material wherein the barrier performance is improved, according to one set of embodiments.

[0121] The disclosed barrier coatings may contain a low density of pinholes, or may be pinhole free, so they provide superior barrier properties to protect the products that are packaged within the flexible material or materials. Barrier may refer to water-vapor barrier or oxygen barrier but is not thus limited. These barrier properties prevent moisture, oxygen, and other external elements from entering the package to keep the products fresh and may extend the shelf life of products, such as food.

[0122] At least in part because of the low density of pinholes, a barrier coating may have a relatively high density (relative to the bulk density of the materials used in the barrier coating). In some embodiments, a barrier coating has a density of greater than or equal to 50%, greater than or equal to 55%, greater than or equal to 60%, greater than or equal to 65%, greater than or equal to 70%, greater than or equal to 75%, greater than or equal to 80%, greater than or equal to 85%, greater than or equal to 90%, or greater than or equal to 95% of the bulk density of the barrier coating. In some embodiments, a barrier coating has a density of less than or equal to 100%, less than or equal to 95%, less than or equal to 90%, less than or equal to 85%, less than or equal to 80%, less than or equal to 75%, less than or equal to 70%, less than or equal to 65%, less than or equal to 60%, or less than or equal to 55% of the bulk density of the barrier coating. Combinations of these ranges are also possible (e.g., greater than or equal to 50% and less than or equal to 100%, or greater than or equal to 50% and less than or equal to 75%). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0123] The disclosed metal-oxide barrier coatings are, in some embodiments, only a few tens of nanometers thick, such that they do not affect the compostability and / or biodegradability and / or recyclability of sustainable packaging materials. Due to their ultra-thin nature, disclosed coatings also do not significantly affect the mechanical flexibility of the packaging materials, according to one set of embodiments.

[0124] Compared to conventional barrier-coating processes, at least some methods provided herein may operate in open-air without a vacuum chamber, reducing the cost of the process and increasing its speed / throughput. The disclosed method is also solvent free, according to one set of embodiments.

[0125] Any of a variety of suitable substrates may be used, depending on the embodiment. Referring again to FIG. 1A, for example, the substrate 104 may be flexible and may include a substrate, such as polylactic acid (PLA), paper, paperboard, polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polyurethane (PU), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), starch-based polymer, seaweed-based polymer, or similar. The disclosed methods and systems may, in some cases, allow a functional coating to be applied directly (with or without a primer) on flexible materials such as polyethylene, polypropylene, polylactic acid, paperboard and kraft paper, or a combination thereof, but not limited to the stated. The substrate 104 may include additional materials or layers thereof, such as an ink layer. The substrate 104 may be selected to be biodegradable, recyclable, or compostable.

[0126] One advantage of the methods provided herein is that the barrier coatings described above may, in some embodiments, be conformal coatings. The use of conformal barrier coatings means that, in some embodiments, the barrier coatings can be applied to comparatively rough substrates.

[0127] A barrier coating may be applied to a substrate with any of a variety of suitable peak-to-valley (P-V) roughnesses. It is contemplated that a substrate 104 with roughness features with a peak or valley size of less than about 0.2 millimeters may be used without undue difficulty. Larger feature sizes (e.g., a peak or valley size of less than about 1 millimeter) are also possible. For example, in some embodiments, a substrate has a P-V roughness of greater than or equal to 10 micrometers, greater than or equal to 30 micrometers, greater than or equal to 50 micrometers, greater than or equal to 100 micrometers, greater than or equal to 150 micrometers, greater than or equal to 200 micrometers, greater than or equal to 500 micrometers, or more. In some embodiments, a substrate has a P-V roughness of less than or equal to 1000 micrometers, less than or equal to 500 micrometers, less than or equal to 200 micrometers, less than or equal to 150 micrometers, less than or equal to 100 micrometers, less than or equal to 50 micrometers, less than or equal to 30 micrometers, or less than or equal to 20 micrometers. Combinations of these ranges are also possible (e.g., greater than or equal to 10 micrometers and less than or equal to 1000 micrometers, greater than or equal to 20 micrometers and less than or equal to 200 micrometers, or greater than or equal to 50 micrometers and less than or equal to 200 micrometers). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0128] A barrier coating may be applied to a substrate with any of a variety of suitable root-mean-square (RMS) roughnesses. In some embodiments, a substrate has an RMS roughness of greater than or equal to 5 micrometers, greater than or equal to 10 micrometers, greater than or equal to 15 micrometers, greater than or equal to 20 micrometers, greater than or equal to 25 micrometers, greater than or equal to 30 micrometers, greater than or equal to 35 micrometers, greater than or equal to 40 micrometers, greater than or equal to 45 micrometers, greater than or equal to 50 micrometers, greater than or equal to 55 micrometers, greater than or equal to 60 micrometers, greater than or equal to 65 micrometers, greater than or equal to 70 micrometers, greater than or equal to 75 micrometers, greater than or equal to 80 micrometers, greater than or equal to 85 micrometers, greater than or equal to 90 micrometers, or greater than or equal to 95 micrometers. In some embodiments, a substrate has an RMS roughness of less than or equal to 100 micrometers, less than or equal to 95 micrometers, less than or equal to 90 micrometers, less than or equal to 85 micrometers, less than or equal to 80 micrometers, less than or equal to 75 micrometers, less than or equal to 70 micrometers, less than or equal to 65 micrometers, less than or equal to 60 micrometers, less than or equal to 55 micrometers, less than or equal to 50 micrometers, less than or equal to 45 micrometers, less than or equal to 40 micrometers, less than or equal to 35 micrometers, less than or equal to 30 micrometers, less than or equal to 25 micrometers, less than or equal to 20 micrometers, less than or equal to 15 micrometers, or less than or equal to 10 micrometers. Combinations of these ranges are also possible (e.g., greater than or equal to 5 micrometers and less than or equal to 100 micrometers, greater than or equal to 10 micrometers and less than or equal to 100 micrometers, or greater than or equal to 25 micrometers and less than or equal to 100 micrometers). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0129] In some embodiments, even with a substrate having a roughness within one of the forgoing ranges, the barrier coating has a relatively uniform thickness. For example, as described above, in some embodiments the substrate has an RMS roughness of greater than or equal to 5 micrometers but the thickness of the barrier coating varies by less than 100% from an average value of the thickness of the barrier coating.

[0130] It may be advantageous for any pores or pinholes in a substrate to be relatively small, e.g., since relatively small pinholes can be closed by the barrier coating. It is contemplated that, if the substrate 104 has pinholes, the pinholes should have a nominal width of less than about 25 nanometers, so that the barrier coating 102 may close the pinholes reliably. In some embodiments, a substrate has an average pinhole width of less than or equal to 25 nm, less than or equal to 20 nm, less than or equal to 15 nm, less than or equal to 10 nm, less than or equal to 9 nm, less than or equal to 8 nm, less than or equal to 7 nm, less than or equal to 6 nm, less than or equal to 5 nm, less than or equal to 4 nm, less than or equal to 3 nm, or less than or equal to 2 nm. In some embodiments, a substrate has an average pinhole width of greater than or equal to 1 nm, greater than or equal to 2 nm, greater than or equal to 3 nm, greater than or equal to 4 nm, greater than or equal to 5 nm, greater than or equal to 6 nm, greater than or equal to 7 nm, greater than or equal to 8 nm, greater than or equal to 9 nm, greater than or equal to 10 nm, greater than or equal to 15 nm, or greater than or equal to 20 nm. Combinations of these ranges are also possible (e.g., greater than or equal to 1 nm and less than or equal to 25 nm, greater than or equal to 1 nm and less than or equal to 10 nm, greater than or equal to 1 nm and less than or equal to 8 nm, or greater than or equal to 1 nm and less than or equal to 5 nm). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited. In some embodiments, a substrate with comparatively wide pores can be calendared to ensure that pinholes have a relatively small width (e.g., an average width within one of the forgoing ranges).

[0131] However, the present disclosure recognizes that substrates with larger pinholes may also be coated, e.g., by using a primer layer to cover pinholes. For example, in some embodiments, the substrate has pinholes having an average width of greater than or equal to 25 nm, greater than or equal to 30 nm, greater than or equal to 40 nm, greater than or equal to 50 nm, greater than or equal to 60 nm, greater than or equal to 70 nm, greater than or equal to 80 nm, greater than or equal to 90 nm, greater than or equal to 100 nm, greater than or equal to 110 nm, greater than or equal to 120 nm, greater than or equal to 130 nm, greater than or equal to 140 nm, greater than or equal to 150 nm, greater than or equal to 160 nm, greater than or equal to 170 nm, greater than or equal to 180 nm, or greater than or equal to 190 nm. In some embodiments, the substrate has pinholes having an average width of less than or equal to 200 nm, less than or equal to 190 nm, less than or equal to 180 nm, less than or equal to 170 nm, less than or equal to 160 nm, less than or equal to 150 nm, less than or equal to 140 nm, less than or equal to 130 nm, less than or equal to 120 nm, less than or equal to 110 nm, less than or equal to 100 nm, less than or equal to 90 nm, less than or equal to 80 nm, less than or equal to 70 nm, less than or equal to 60 nm, less than or equal to 50 nm, less than or equal to 40 nm, or less than or equal to 30 nm. Combinations of these ranges are also possible (e.g., greater than or equal to 25 nm and less than or equal to 200 nm, greater than or equal to 25 nm and less than or equal to 80 nm, or greater than or equal to 25 nm and less than or equal to 50 nm). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0132] Suitable primer layers that may be used to cover substrates with large pinholes are described in greater detail below.

[0133] Useful substrates may have a broad range of surface chemistries. According to some embodiments, oxygen (O) groups (e.g., =0 groups or -OH groups) at the surface are particularly useful. A precursor chemical used when forming the barrier coating may react with O groups, which facilitates coating deposition. Examples of substrate materials and primers that have such O groups include PLA, PET, polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), and acrylic, for example. No particular treatment to enhance surface energy is required for the substrate, as it has been found that, according to one set of embodiments, the barrier coating adheres satisfactorily to the substrate without such treatment. However, without wishing to be bound by any particular theory, O-groups may be capable of reacting with a barrier coating precursor to form chemical bonds, and may thus improve adhesion between the barrier coating and the substrate.

[0134] Regarding thermomechanical properties of the substrate, in many examples it is useful if the substrate does not bulge significantly when heated. Advantageous substrates can, in some embodiments, retain their shape without deforming at least up to the desired coating temperature. For example, it may be advantageous for the glass transition temperature of the substrate to exceed the coating temperature, depending on the embodiment. Without wishing to be bound by any particular theory, a lower coefficient of thermal expansion (CTE) of the substrate may advantageously reduce the chance of thermal stress cracking of the barrier coating due to CTE mismatch between the barrier coating and the substrate. In various examples, the substrate material is selected to have a CTE that is consistent with or lower than a CTE of PP, PE, PLA, PVOH, or PU.

[0135] Surface cleanliness of the substrate may help ensure the quality of the coating, such as consistency, uniformity, pinhole-free, adhesion, etc. Apart from surface cleanliness, different substrate materials have different surface chemistries which affect the properties of the coating such as, but not limited to adhesion, morphology, density, and crystallinity. Substrates with suitable properties may be chosen for a desired barrier coating, depending on the embodiment.

[0136] Also disclosed herein are cleaning methods, using several purge and exhaust steps, which may be used prior to the deposition process to improve surface cleanliness. In some embodiments, for example, the surface of the substrate may be treated to improve cleanliness. For example, surface treatment such as, but not limited to, corona, plasma, and dielectric barrier discharge, can be used to prime the substrate surface to enhance the coating process and coating properties. For example, in some embodiments ozone and plasma treatment can improve the surface chemistry of some substrates, such as polyethylene, for better coating quality that improves barrier performance. Plasma ALD may be used to coat materials with challenging surface chemistry. Plasma treatment may, in some cases, advantageously lower the temperature required for deposition of materials and / or increase the density of the resultant coatings, relative to coatings deposited by other treatments. Other treatments, such as flame treatments, are also possible, depending on the embodiment.

[0137] The substrate layer itself may have any of a variety of properties suitable for packaging applications. For example, a substrate may have any of a variety of suitable average areal densities. In some embodiments, a substrate (e.g., a paper substrate, a plastic substrate) has an average areal density of greater than or equal to 10 grams / meter2(“gsm”), greater than or equal to 20 gsm, greater than or equal to 30 gsm, greater than or equal to 40 gsm, greater than or equal to 50 gsm, greater than or equal to 60 gsm, greater than or equal to 70 gsm, greater than or equal to 80 gsm, greater than or equal to 90 gsm, greater than or equal to 100 gsm, or greater than or equal to 110 gsm. In some embodiments, a substrate (e.g., a paper substrate, a plastic substrate) has an average areal density of less than or equal to 120 gsm, less than or equal to 110 gsm, less than or equal to 100 gsm, less than or equal to 90 gsm, less than or equal to 80 gsm, less than or equal to 70 gsm, less than or equal to 60 gsm, less than or equal to 50 gsm, less than or equal to 40 gsm, less than or equal to 30 gsm, or less than or equal to 20 gsm. Combinations of these ranges are also possible (e.g., greater than or equal to 10 gsm and less than or equal to 120 gsm, greater than or equal to 30 gsm and less than or equal to 90 gsm, or greater than or equal to 50 gsm and less than or equal to 70 gsm). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0138] Likewise, a substrate layer may have any of a variety of average thicknesses, depending on the embodiment. In some embodiments, a substrate (e.g., a paper substrate, a plastic substrate) has an average thickness of greater than or equal to 10 microns, greater than or equal to 20 microns, greater than or equal to 30 microns, greater than or equal to 40 microns, greater than or equal to 50 microns, greater than or equal to 60 microns, greater than or equal to 70 microns, greater than or equal to 80 microns, greater than or equal to 90 microns, greater than or equal to 100 microns, or greater than or equal to 110 microns. In some embodiments, a substrate (e.g., a paper substrate, a plastic substrate) has an average thickness of less than or equal to 120 microns, less than or equal to 110 microns, less than or equal to 100 microns, less than or equal to 90 microns, less than or equal to 80 microns, less than or equal to 70 microns, less than or equal to 60 microns, less than or equal to 50 microns, less than or equal to 40 microns, less than or equal to 30 microns, or less than or equal to 20 microns. Combinations of these ranges are also possible (e.g., greater than or equal to 10 microns and less than or equal to 120 microns, greater than or equal to 20 microns and less than or equal to 80 microns, or greater than or equal to 40 microns and less than or equal to 60 microns). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0139] In some aspects, an article provided herein may comprises a primer layer. The primer layer may be disposed between the barrier coating and the substrate, depending on the embodiment. FIG. IB presents shows a non-limiting schematic cross section of an article 100 comprising a barrier coating 102 (like that of FIG. 1 A) disposed on a substrate 104. Unlike in FIG. 1A, in FIG. IB, barrier coating 102 is not directly adjacent substrate 104; rather, article 100 further comprises primer layer 143 disposed between barrier coating 102 and substrate 104. While only one primer layer 143 is shown, it should of course be understood that a plurality of primer layers could be used, some or all of which may be disposed between barrier coating 102 and substrate 104, depending on the embodiment.

[0140] A primer layer may be disposed at least partially (e.g., completely) between the barrier coating and the substrate, according to one set of embodiments. A primer layer may serve any of a variety of suitable purposes. According to some embodiments, a primer layer is configured to adhere a barrier coating to a substrate. Primer layers may be particularly useful in the context of articles used for sustainable packaging. For example, the primer layer may be useful in the context of applying barrier coatings (as described above) to paper, cardboard, or other substrates comprising webs of cellulose fibers, as well as in the context of other porous materials (e.g., porous plastic substrates). In some embodiments, the primer layer is configured to cover pinholes or other pores in the substrate, leaving a relatively pinhole-free surface available for coating. According to some embodiments, a primer layer is introduced to cover pinholes in a substrate. A primer layer may, in some embodiments, promote the adhesion of the barrier coating and the substrate, e.g., by binding more effectively to the barrier coating than would the bare substrate.

[0141] Another, unexpected, advantage of a primer layers, recognized herein, is that primer layers may help to improve the barrier performance of barrier coatings under humid or wet conditions. It has been recognized, that in some cases, substrates undergo physical changes in response to exposure to water. For example, in some embodiments, some substrates (e.g., substrates comprising a web of cellulose, such substrates including paper, cardboard, paperboard, and kraft paper) may swell when exposed to moisture. For example, such substrates may undergo hygroexpansion when wetted. Without wishing to be bound by any particular theory, in some embodiments hygroexpansion may cause the substrate to expand faster than the barrier coating, straining and / or fracturing the barrier coating in response to dimensional changes of the substrate resulting from moisture exposure. It has been recognized herein that a primer layer may, in some embodiments act as a moisture seal, reducing or preventing substrate hygroexpansion. Accordingly, in some embodiments primer layers provided herein may provide improved barrier performance, e.g., by helping the barrier coating retain structural integrity under humid or moist conditions.

[0142] According to some embodiments, an article comprises a plurality of primer layers. For example, the article may comprise a first primer layer, a second primer layer, a third primer layer, etc. The layers may provide similar or different functions, depending on the embodiment. For example, in some embodiments, the plurality of primer layers are compositionally similar and are layered for improved thickness / reduced water penetration. However, in some embodiments, the plurality of primer layers serve different functions. For example, in some embodiments a first primer layer directly adjacent to the substrate is a conformal base layer, while a second primer layer disposed on top of the first primer layer configured to fill or cover pinholes left in the first layer. In some embodiments, the article comprises a third primer layer deposited on the second primer layer, and configured, e.g., to act as an additional barrier or provide better adhesion to a barrier coating deposited on the third primer layer. Layers designed to serve different roles may have different compositions.

[0143] Any of a variety of suitable materials may be used for primer layers. In some embodiments, a primer layer comprises a polymer. For example, in some embodiments a primer layer is a polymeric layer. Non-limiting examples of suitable polymers include, but are not limited to, PVOH, EVOH, acrylic, polyurethane (PU), nanocellulose / micro fibrillated cellulose, PLA, and PE. Non-polymeric materials (e.g., ceramic materials) may also be used. For example, in some embodiments, the primer layer comprises clay.

[0144] In some embodiments, a primer layer comprises multiple polymers. Primer layers may be water soluble or water insoluble. Non-limiting examples of polymers that may be used in primer layers include, but are not limited to: polyvinyl alcohol (PVOH), ethylene vinyl alcohol (EVOH), proteins (e.g., casein, legume protein, soy protein, corn zein, or whey protein), polysaccharides (e.g., starch (e.g., potato starch), cellulose (e.g., nanocellulose, microfibrillated cellulose), starch, pectin, guar gum, alginate, or chitosan), olefins (e.g., polyethylene, polypropylene, polystyrenes, polybutadiene, polymers or copolymers of alpha-olefins (e.g., 1-hexene or 1-butene)), ethylene (meth)acrylic acid, polyamides, polyesters (e.g., polyethylene terephthalate), polyacrylics, polymethacrylic acids (e.g., poly ethylene (meth)acrylic acid), poly(vinyl halides), poly(vinyl nitriles), poly(vinyl esters), polycarbonates, polyurethanes, polysiloxanes, polysulfones, polysulfonamides, polyimines, latex, cellulose derivatives (e.g., ethyl cellulose, methyl cellulose), rosin ester and mixtures or copolymers thereof. Polymers that may be of particular interest include, but are not limited to, PVOH, EVOH, proteins, polysaccharides (e.g., nanocellulose, microfibrillated cellulose), styrene- acrylate copolymers, carboxylated polystyrene, acrylic, polyvinyl acetate, polyvinylacetateethylene, poly vinylacrylic, soy protein, corn zein, starch, polypropylene, rosin-ester, and combinations thereof.

[0145] In some embodiments, a primer layer comprises a wax (e.g., beeswax).

[0146] In an exemplary set of embodiments, a primer layer comprises a cellulose (e.g., nanocellulose or microfibrillated cellulose) together with a second polymer. In some embodiments, the second polymer is an EVOH copolymer. The EVOH copolymer may have any of a variety of suitable ethylene contents. For example, in some embodiments, an EVOH copolymer of a primer layer comprises ethylene in an amount of greater than or equal to 20 mol%, greater than or equal to 25 mol%, greater than or equal to 30 mol%, greater than or equal to 35 mol%, greater than or equal to 40 mol%, greater than or equal to 45 mol%, or greater than or equal to 50 mol%. In some embodiments, an EVOH copolymer of a primer layer comprises ethylene in an amount of less than or equal to 55 mol%, less than or equal to 50 mol%, less than or equal to 45 mol%, less than or equal to 40 mol%, less than or equal to 35 mol%, less than or equal to 30 mol%, or less than or equal to 25 mol%. Combinations of these ranges are also possible (e.g., greater than or equal to 20 mol% and less than or equal to 55 mol%, or greater than or equal to 25 mol% and less than or equal to 50 mol%). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0147] In some embodiments, the primer comprises a coating derived from a natural material (e.g., comprising a polymer or fiber from seaweed, pineapple skin, or a shellfish shell).

[0148] The polymer (e.g., the EVOH) of the primer layer may have any of a variety of suitable molecular weights. In some embodiments, a polymer of a primer layer has a weight average molecular weight (Mw) of greater than or equal to 85 kDa, greater than or equal to 90 kDa, greater than or equal to 95 kDa, greater than or equal to 100 kDa, greater than or equal to 105 kDa, greater than or equal to 110 kDa, greater than or equal to 115 kDa, greater than or equal to 120 kDa, or greater than or equal to 125 kDa. In some embodiments, a polymer of a primer layer has a weight average molecular weight of less than or equal to 130 kDa, less than or equal to 125 kDa, less than or equal to 120 kDa, less than or equal to 115 kDa, less than or equal to 110 kDa, less than or equal to 105 kDa, less than or equal to 100 kDa, less than or equal to 95 kDa, or less than or equal to 90 kDa. Combinations of these ranges are also possible (e.g., greater than or equal to 85 kDa and less than or equal to 130 kDa, or greater than or equal to 90 kDa and less than or equal to 125 kDa). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0149] In some embodiments, a polymer of a primer layer has a number average molecular weight (MN) of greater than or equal to 40 kDa, greater than or equal to 45 kDa, greater than or equal to 50 kDa, greater than or equal to 55 kDa, greater than or equal to 60 kDa, or greater than or equal to 65 kDa. In some embodiments, a polymer of a primer layer has a number average molecular weight of less than or equal to 70 kDa, less than or equal to 65 kDa, less than or equal to 60 kDa, less than or equal to 55 kDa, less than or equal to 50 kDa, or less than or equal to 45 kDa. Combinations of these ranges are also possible (e.g., greater than or equal to 40 kDa and less than or equal to 70 kDa, or greater than or equal to 45 kDa and less than or equal to 65 kDa). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0150] In some embodiments, a primer layer does not contain a polymer. For example, according to some embodiments, the disclosure provides primers comprising one or more fatty acids or salts thereof. A primer layer may comprise a fatty acid and / or a fatty acid salt in addition to or as an alternative to a polymer, depending on the embodiment. The use of a fatty acid or fatty acid salt may provide a number of advantages, depending on the embodiment. For example, when used in combination with a polymer, the polymer may provide structural support, while the fatty acid or fatty acid salt may help to provide waterproofing may act as a plasticizer, according to some embodiments. In some embodiments, e.g., where a fatty acid or fatty acid salt is used without a polymer, the fatty acid or fatty acid salt may offer certain processing advantages. For example, the fatty acid or fatty acid salt may be liquid processable. Liquid processibility of a primer may, advantageously, simplify integration of a primer deposition process into a barrier coating deposition process, e.g., since the substrate may not need to be baked to high temperatures during processing.

[0151] A fatty acid or fatty acid salt for use in a primer layer may be a saturated or unsaturated fatty acid comprising an aliphatic tail of 9 to 21 carbon atoms (e.g., an aliphatic tail of 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21 carbon atoms). A few, non-limiting examples of fatty acids that may be used in a primer layer include, but are not limited to, mystyric acid, palmitic acid, and stearic acid. A few non-limiting examples of fatty acid salts that may be used in a primer layer include, but are not limited to, stearates (e.g., sodium stearate, potassium stearate, zinc stearate), myristates (e.g., sodium myristate, potassium myristate, calcium myristate, or zinc myristate), and palmitates, (e.g., sodium palmitate, potassium palmitate, calcium palmitate, or zinc palmitate).

[0152] In some embodiments, the primer comprises a plurality of metal ions having an oxidation state of at least +3. According to some embodiments, a fatty acid used in a primer is complexed with a metal ion having an oxidation state of at least +3. Any of a variety of suitable metals may be complexed with fatty acids of a primer, including chromium, titanium, and / or iron. In some embodiments, the complex is a Werner chrome complex of the fatty acid and the metal (e.g., a Quilon™ metal complex such as Quilon™ C, Quilon™ M, Quilon™ L, Quilon™ H, or Quilon™ S). As an example, a fatty acid may be complexed with metal ions as shown in Formula (1) below: where Ri is an aliphatic tail of 9 to 21 carbon atoms, M is a metal ion having an oxidation state of at least +3 (the complex comprises 2 M ions), X is a halogen (e.g., chlorine), and R2OH is a suitable solvent (e.g., water, or an alcohol such as methanol or ethanol).

[0153] The complexes described above may be included directly in the primer composition. In some embodiments, a complex described above is used during deposition of the primer layer, and a reaction product thereof is included in the primer.

[0154] Non-polymeric materials (e.g., ceramic materials) may also be used in a primer, depending on the embodiment. The non-polymeric materials may serve any of a variety of roles. For example, in some embodiments, the non-polymeric materials comprise a pigment, e.g., for coloration of the primer. Without wishing to be bound by any particular theory, in some embodiments, the use of non-polymeric materials (e.g., non- polymeric particles) may help to cover pinholes in the substrate. For example, according to some embodiments, a primer layer designed to cover pinholes in a directly adjacent substrate or primer layer may comprise a plurality of non-polymeric particles, e.g., to provide mechanical support to the primer straddling the pinholes. In some embodiments, the non-polymeric materials are simply used as filler, e.g., for reducing primer cost. Other advantages of non-polymeric materials are also possible.

[0155] Any of a variety of non-polymeric materials may be used. A few, non-limiting examples of non-polymeric materials that can be incorporated into a primer include, but are not limited to: pigments and / or mineral particles (such as clays and / or mineral particles comprising aluminum or aluminium oxide (e.g., kaolin clay), silicates, calcium carbonate). Other non polymeric materials are also possible and those of ordinary skill in the art would be capable of selecting such non polymeric materials based upon the teachings of this specification.

[0156] In one set of exemplary embodiments, a layered article comprises, in order: a substrate, a first primer layer, a second primer layer, and a barrier coating. The first primer layer may be directly adjacent to the substrate. The first primer layer may comprise cellulose and a first polymer such as EVOH or a copolymer thereof. In some embodiments, the first primer layer comprises a second polymer comprising polystyrene or a copolymer thereof. The second primer layer may be directly adjacent to the first primer layer, e.g., so that at least a portion of the first primer layer is disposed between the second primer layer and the substrate. The second primer layer may be configured to eliminate pinholes in the first primer layer. The second primer layer may comprise a first polymer comprising a polysaccharide or a protein and, optionally a second polymer EVOH or a copolymer thereof, wherein the first polymer is mixed with a second polymer (if present). The first polymer may comprise casein, legume protein, or whey protein. In some embodiments, the second primer layer comprises mineral particles comprising aluminum or aluminum oxide. According to some embodiments, the second primer layer comprises a fatty acid. Optionally, the primer may comprise a third primer layer. The third primer layer may be directly adjacent to the second primer layer, on a side of the second primer layer opposite the first primer layer and the substrate, e.g., so that the second primer layer is disposed between and directly adjacent to the first primer layer and the third primer layer. The third primer layer may have a composition similar to that of the first primer layer or the second primer layer. In some embodiments, the third primer layer has a different composition. The third primer layer may be a water repellant layer, according to some embodiments. For example, the third primer layer may be a layer having a water absorption after 24 hours at 38° C and 90% relative humidity of less than or equal to 5%.

[0157] In another set of exemplary embodiments, a layered article comprises a primer layer comprising: (i) a first fatty acid or a salt thereof; and (ii) at least one of a polymer (e.g,. PVOH) and a complex of a fatty acid with a metal ion having an oxidation state of at least +3. According to some embodiments, the weight ratio of (i) the first fatty acid or salt thereof to (ii) the PVOH and / or the complex is in the range of about 5:1 to 20:1. According to some embodiments, the salt of the first fatty acid is a salt of one or more of myristic, palmitic and stearic acid. In some embodiments, the primer layer further comprises (iii) a second polymer or copolymer (e.g., polystyrene or a copolymer thereof). Such a combination may be advantageous for the deposition of water-repellant primers via liquid processing. For example, in some embodiments, the primer may be deposited using discrete spheres that coalesce to form a continuous primer layer after deposition in an aqueous liquid.

[0158] Suitable primer layers that may be used to cover substrates with large pinholes are described in greater detail below.

[0159] A polymer may have any of a variety of suitable arial densities in the primer layer. In some embodiments, a primer layer has an arial density of greater than or equal to 0.5 g / m2, greater than or equal to 1 g / m2, greater than or equal to 2 g / m2, greater than or equal to 3 g / m2, greater than or equal to 4 g / m2, greater than or equal to 5 g / m2, greater than or equal to 6 g / m2, greater than or equal to 7 g / m2, greater than or equal to 8 g / m2, greater than or equal to 9 g / m2, greater than or equal to 10 g / m2, greater than or equal to 11 g / m2, greater than or equal to 12 g / m2, greater than or equal to 13 g / m2, greater than or equal to 14 g / m2, greater than or equal to 15 g / m2, greater than or equal to 16 g / m2, greater than or equal to 17 g / m2, greater than or equal to 18 g / m2, or greater than or equal to 19 g / m2. In some embodiments, a primer layer has an arial density of less than or equal to 20 g / m2, less than or equal to 19 g / m2, less than or equal to 18 g / m2, less than or equal to 17 g / m2, less than or equal to 16 g / m2, less than or equal to 15 g / m2, less than or equal to 14 g / m2, less than or equal to 13 g / m2, less than or equal to 12 g / m2, less than or equal to 11 g / m2, less than or equal to 10 g / m2, less than or equal to 9 g / m2, less than or equal to 8 g / m2, less than or equal to 7 g / m2, less than or equal to 6 g / m2, less than or equal to 5 g / m2, less than or equal to 4 g / m2, less than or equal to 3 g / m2, or less than or equal to 2 g / m2. Combinations of these ranges are also possible (e.g., greater than or equal to 0.5 g / m2and less than or equal to 20 g / m2, greater than or equal to 2 g / m2and less than or equal to 8 g / m2, or greater than or equal to 3 g / m2and less than or equal to 6 g / m2). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0160] According to some embodiments, a primer layer is configured to have a relatively low water absorption. For example, according to some embodiments, a primer layer, maintained for a duration of at least 24 hours at 38 °C at 90% relative humidity, has a water absorption of less than or equal to 5 wt%, less than or equal to 4.5 wt%, less than or equal to 4 wt%, less than or equal to 3.5 wt%, less than or equal to 3 wt%, less than or equal to 2.5 wt%, less than or equal to 2 wt%, less than or equal to 1.5 wt%, or less than or equal to 1 wt% versus the dry weight of the primer layer. In some embodiments, a water absorption of the primer layer, maintained for a duration of at least 24 hours at 38 °C at 90% relative humidity, has a water absorption of greater than or equal to 0.5 wt%, greater than or equal to 1 wt%, greater than or equal to 1.5 wt%, greater than or equal to 2 wt%, greater than or equal to 2.5 wt%, greater than or equal to 3 wt%, greater than or equal to 3.5 wt%, greater than or equal to 4 wt%, or greater than or equal to 4.5 wt% versus the dry weight of the primer layer. Combinations of these ranges are also possible (e.g., greater than or equal to 0.5 wt% and less than or equal to 5 wt%, or greater than or equal to 0.5 wt% and less than or equal to 3 wt%). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited. According to some embodiments, an outermost primer layer (i.e., a primer layer that is furthest separated from the substrate) is selected to have a relatively low water absorption falling within one of the foregoing ranges, e.g., so that the primer is an effective water-proofing layer.

[0161] Suitable primer layers may have pinholes with any of a variety of suitable average diameters. In some embodiments, a primer layer has an average pinhole width of less than or equal to 25 nm, less than or equal to 20 nm, less than or equal to 15 nm, less than or equal to 10 nm, less than or equal to 9 nm, less than or equal to 8 nm, less than or equal to 7 nm, less than or equal to 6 nm, less than or equal to 5 nm, less than or equal to 4 nm, less than or equal to 3 nm, or less than or equal to 2 nm. In some embodiments, a primer layer has an average pinhole width of greater than or equal to 1 nm, greater than or equal to 2 nm, greater than or equal to 3 nm, greater than or equal to 4 nm, greater than or equal to 5 nm, greater than or equal to 6 nm, greater than or equal to 7 nm, greater than or equal to 8 nm, greater than or equal to 9 nm, greater than or equal to 10 nm, greater than or equal to 15 nm, or greater than or equal to 20 nm. Combinations of these ranges are also possible (e.g., greater than or equal to 1 nm and less than or equal to 25 nm, greater than or equal to 1 nm and less than or equal to 10 nm, greater than or equal to 1 nm and less than or equal to 8 nm, or greater than or equal to 1 nm and less than or equal to 5 nm). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0162] A primer may be configured to be relatively hydrophobic. In some embodiments, for example, a primer is configured to have a relatively high contact angle with water. In some embodiments, a primer layer has a contact angle of greater than or equal to 60°, greater than or equal to 70°, greater than or equal to 80°, greater than or equal to 90°, greater than or equal to 100°, greater than or equal to 110°, greater than or equal to 120°, greater than or equal to 130°, greater than or equal to 140°, greater than or equal to 150°, greater than or equal to 160°, or greater than or equal to 170°. In some embodiments, a primer layer has a contact angle of less than or equal to 180°, less than or equal to 170°, less than or equal to 160°, less than or equal to 150°, less than or equal to 140°, less than or equal to 130°, less than or equal to 120°, less than or equal to 110°, less than or equal to 100°, less than or equal to 90°, less than or equal to 80°, or less than or equal to 70°. Combinations of these ranges are also possible (e.g., greater than or equal to 60° and less than or equal to 180°, or greater than or equal to 90° and less than or equal to 170°). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0163] According to some embodiments, it may be advantageous for a primer layer to be configured to react with a barrier coating precursor, e.g., to promote adhesion between the primer layer and the barrier coating. For example, the primer layer may comprise O- groups (e.g., =0 groups, -OH groups) capable of reacting with a barrier coating precursor to form chemical bonds. Such a primer layer may, advantageously, directly bond to the barrier coating, improving adhesion of the barrier coating to the substrate. However, it should of course be understood that this is not necessary, and that embodiments where the layer is formed without chemical binding of the primer layer to the barrier coating are also possible. For example, without wishing to be bound by any particular theory, in some embodiments, the primer layer may be configured to adhere to the barrier coating by interpenetrating with the barrier coating (e.g., where diffusion of precursors of the barrier coating into the primer layer was used to initiate the barrier coating onto the primer layer).

[0164] It should, of course, be understood that a primer layer is neither needed nor contemplated in all embodiments. In some embodiments, for example, a substrate is configured such that it is relatively free of pinholes or other pores — even when the substrate comprises a sustainable material. For example, in some embodiments, the substrate or a surface thereof is calendered to make it less porous, as described above.

[0165] In addition to barrier coatings and substrates, a multilayered article may include any of a variety of suitable additional layers. In some embodiments, an additional layer may be used to cure defects in a substrate. As discussed in the context of the examples below, in some embodiments it has been recognized that some coatings may be relatively conformal, meaning that larger pinholes may be conformally coated rather than layered over during deposition. Consequently, pinholes in the substrate may result in formation of a porous barrier coating.

[0166] In some embodiments, an article comprises a layer configured to help with forming the article into a package. For example, in some embodiments, the article comprises a sealant layer, e.g., disposed on at least a portion of (e.g., disposed on an entire side of) an article. The sealant layer may be configured such that under the right conditions, it fuses or adheres to itself or another sealant layer to form a seal. Such a sealant layer may provide any of a variety of advantages for forming packages of the types detailed below. For example, in some embodiments one or more articles may be sealed together to form a container. In at least some embodiments, at least a portion of the container (e.g., an edge or a fold of the container) is sealed via adhesion of a first sealant layer to itself or another sealant layer.

[0167] According to some embodiments, the sealant layer is adjacent to the barrier coating. Such configurations may provide particular advantages for packaging applications. For example, the sealant layer may be used to forgo the use of an additional substrate layer, protecting the barrier coating, reducing cost, and / or simplifying package design, in at least some embodiments. According to some embodiments, therefore, the sealant layer is adjacent (e.g., directly adjacent) to the barrier coating of the article.

[0168] Any of a variety of suitable materials may be used for sealant layers. For example, in some embodiments a sealant layer is a polymeric layer. For example, in some embodiments, the sealant layer comprises a thermoplastic polymer (e.g., polyethylene. For example, in some embodiments, the sealant is applied via a solution processing technique (e.g., by applying a wet coating that is subsequently dried and may ultimately be laminated to form a seal). Of course, in some embodiments, the sealant is applied via a melt-processing technique, or by any of a variety of other suitable solvent processing techniques known to those of ordinary skill in the art.

[0169] Any of a variety of methods may be used to seal a sealant layer. For example, in some embodiments, a sealant layer is laminated, adhered, pouch sealed, or heated while in contact with another sealant layer to form a seal joining the sealant layers.

[0170] FIGS. 4-7 provide non-limiting schematic illustrations of various packaging articles that may be prepared using the systems, methods, and barrier coatings provided herein.

[0171] FIG. 4 shows an exemplary article 400, such as a packaging film, that uses a barrier coating 102 discussed above. The barrier coating 102 is applied to a first substrate that includes a substrate 402, such as paper, PLA, etc. (see above for more examples). The barrier coating 102 may be deposited directly onto the substrate 402. The article 400 includes an additional, second substrate that includes a substrate 404 and an ink layer 306 disposed on the substrate 404. The substrate 404 may be paper, PLA, etc.

[0172] The ink layer 406 may be printed onto the substrate 404. The ink layer 406 may not completely cover the substrate 404. That is, ink may be selectively deposited to form imagery and text, leaving some of the substrate 404 exposed. Ink layer 406 may be printed on the same side of the substrate as barrier coating 102 or on the opposite side of the substrate from barrier coating 102, depending on the embodiment.

[0173] The article 400 further includes an adhesive layer 408 that adheres the second substrate formed of the substrate 404 and ink layer 406 to the barrier coating 102. The adhesive layer 408 joins the first substrate (i.e., substrate 402) with the barrier coating 102 to the second substrate (i.e., substrate 404 and ink layer 406). The adhesive layer 408 may be applied after the two portions of the article 400 are individually completed.

[0174] FIG. 5, similarly, shows an example article 500, such as a packaging film, that uses a barrier coating 102 discussed above.

[0175] The article 500 includes a first substrate that includes a substrate 502 and an ink layer 504. The substrate 502 may be paper, PLA, etc. (see above for more examples). Ink may be printed onto the substrate 502 to form the ink layer 504. Depending on the amount of printing, the ink layer 504 may not completely cover the substrate 502.

[0176] The article 500 includes a first substrate that includes a substrate 502 and an ink layer 504. The substrate 502 may be paper, PLA, etc. (see above for more examples). Ink may be printed onto the substrate 502 to form the ink layer 504. Depending on the amount of printing, the ink layer 504 may not completely cover the substrate 502.

[0177] The barrier coating 102 is deposited on the first substrate. More specifically, the barrier coating 102 is deposited onto the ink layer 504 and onto any portion of the substrate 502 that is not covered by the ink layer 504.

[0178] The article 500 includes an additional, second substrate that includes a substrate 506, such as paper, PLA, etc. (see above for more examples).

[0179] An adhesive layer 508 adheres the first substrate (i.e., substrate 502 and ink layer 504) with the barrier coating 102 to the second substrate (i.e., substrate 506). The adhesive layer 508 may be applied after the two portions of the article 500 are individually completed.

[0180] FIG. 6 shows an example article 600, such as a packaging film, that uses a barrier coating 102 discussed above. The article 600 includes a first substrate that includes a substrate 602, such as paper, PLA, etc. (see above for more examples). The barrier coating 102 may be deposited directly onto the substrate 602. The article 600 includes an ink layer 604 disposed on the barrier coating 102. Ink may be printed onto the barrier coating 102 to form the ink layer 604. Depending on the amount of printing, the ink layer 604 may not completely cover the barrier coating 102.

[0181] The article 600 further includes an additional, second substrate that includes a substrate 606, such as paper, PLA, etc. (see above for more examples).

[0182] An adhesive layer 608 adheres the second substrate to the first substrate. That is, the adhesive layer 608 bonds the substrate 606 to the ink layer 604 and any portion of the barrier coating 102 that is not covered by the ink layer 604. The adhesive layer 608 may be applied after the two portions of the article 200 are individually completed.

[0183] The example articles 400, 500, 600 may further include a heat-sealing layer, such as a layer of PE, applied to the exposed face of a substrate to facilitate heat sealing a package closed, which is particularly useful for food packaging.

[0184] The example articles 400, 500, 600 may be considered 2-ply articles, in that each substrate with its accompanying layer(s) forms one ply. In other examples, a similar article may be provided with any suitable number of additional plies, such as a ply of plastic, aluminum foil, or functionalized article, to form a 3- or 4-ply article that provides similar utility and benefit.

[0185] FIG. 7 shows an example article 700, such as a packaging article, that uses a barrier coating 102 discussed above. The article 700 includes a substrate that includes a substrate 702 and a pre-coat 704. The barrier coating 102 is deposited on the pre-coat 704 , which may be termed a primer. The pre-coat 704 is useful to fill pores in a paper substrate, create a smooth and even layer for the barrier coating 102, provide compatible surface chemistry for the barrier coating (e.g., a primer with an oxygen group when the barrier coating 102 includes a metal oxide). Example materials for the pre-coat 704 include PVOH, EVOH, acrylic, polyurethane (PU), nanocellulose / micro fibrillated cellulose, PLA coating, PE coating, or similar.

[0186] The article 700 further includes a top coat 706 disposed on the barrier coating 102. The top coat 706 may be useful to protect the barrier coating 102 from downstream processes, such as conveyance. For example, if the barrier coating 102 touches a roller it may be damaged (e.g., scratched). A suitable top coat 706 may protect against such damage. A suitable top coat 706 may improve resistance against flexure failure of the barrier coating 102.

[0187] In some embodiments, a top coat is used to protect an ink layer. For example, where the ink layer is on the same side of the substrate as the barrier coating, the top layer may protect the ink layer and the barrier coating. When the barrier coating and the ink layer are provided on opposite sides of the substrate, a top coat may be provide on one or both sides of the substrate (e.g., to protect the ink layer and / or the barrier coating). In some embodiments, the top coat comprises a varnish. The varnish may comprise a resin (e.g., a polymeric resin) in some embodiments. According to some embodiments, the varnish may act as a secondary moisture and / or oxygen barrier.

[0188] A top coat 706 may also provide separation from particulates found in inks which could damage the barrier coating 102. As such, a top coat 706 may be provided over the barrier coating 102, in this example and in other examples (see FIGS. 4-6) where the barrier coating 102 contacts ink to guard against such damage.

[0189] Example top coats 706 include a PE layer for heat sealing and other materials discussed above as useful for the pre-coat 704.

[0190] In various examples, the top coat 706 may be made of the same material as the substrate 702, which to improve recyclability.

[0191] The example article 700 may be considered a 1 -ply article. In other examples, a similar article may be provided with any suitable number of additional plies, such as a ply of plastic, aluminum foil, or functionalized article, to form a 2-, 3-, or 4-ply article that provides similar utility and benefit.

[0192] An advantage of the barrier coatings provided herein is that they are, in some embodiments, more compostable and / or recyclable than conventional packaging. If the materials disintegrate in the environment, some residue from the aluminum oxide barrier would be left, but its concentration is expected to be less than that already present in soils and meets the ASTM D6400 - 19 (Dec. 23, 2022 version) criteria for compostability. An article provided herein may be compatible with plastic recycling processes. For example, in some embodiments, an article provided herein is compostable such that it meets the ISO 16929 criteria (2021 version) for compostability and is fully compostable within less than or equal to 3 months. In some embodiments, an article provided herein is recyclable such that it meets the Recyclass Standard criteria for recyclability (e.g. the Mar. 2025 version). In some embodiments, an article provided herein is recyclable such that it meets the APR Standard criteria for recyclability (e.g., the Jul. 7, 2025 version). In some embodiments, an article provided herein is compatible with paper recycling processes. For example, an article may be repulpable. In some embodiments, the article is recyclable according to the “‘Voluntary Standard’ for Repulpability & Recyclability of Paper-Based Products” developed by Fibre Box Association (e.g., the Mar. 31, 2025 version).

[0193] Metal-oxide coatings are ceramic and inert and do not cause harm to the environment when the packaging is composted. Furthermore, since the metal-oxide coatings are non-metallic, they allow the packaging to be recycled. Additional advantages of metal-oxide barrier coatings include, but are not limited to, that the coating is microwaveable and can be transparent (i.e., can look into the packaging to see the products).

[0194] In one embodiment of the disclosed coating, the coating provides the disclosed function or functions on sustainable packaging materials that are fully recyclable and / or compostable and / or biodegradable without compromising the recyclability and / or compostability and / or biodegradability of the sustainable packaging materials.

[0195] An article provided herein may be used in any of a variety of packages. For example, in some embodiments, the article is incorporated into a container. The container may comprise a cavity delimited by a wall, wherein the wall comprises an article comprising a substrate and a barrier coating. In some embodiments, the container is a closed container (e.g., wherein the cavity is completely surrounded by the wall such that the wall isolates the cavity from an ambient environment). In some embodiments, the container is open. As yet another example, in some embodiments a container is a resealable container, e.g., which may be closed or open depending on the configuration chosen by a user. The container may comprise one or more multilayered articles, depending on the embodiment. For example, in some embodiments the wall of the container comprises a single, multilayered article situated around the cavity. In some embodiments, the container comprises a plurality of multilayered articles (e.g., which are sealed together). A container may be formed solely using the one or more multilayered articles; however, it should of course be understood that in some embodiments the container may comprise one or more additional articles (e.g., which are not barrier-coated). For example, in some embodiments a container may contain a lid, a fitting, a fastener, an adhesive, or any of a variety of other components that do not comprise barrier coatings, depending on the embodiment.

[0196] A container may have any of a variety of suitable form factors. For example, a container may have any one of the following form factors and may contain a multilayered article as described above: a bottle, a sachet (e.g., a 3-side seal sachet), lidding, a pillow bag, a gusseted bag, a box, a bag, ajar, a can, a pouch, a container, a tray, a tube, a wrap, a pack, a clamshell, a crate, a vacuum-sealed bag, a sleeve, a mold, an envelope, or a carton. An article may cover any of a variety of suitable proportions of the wall of the container, depending on the embodiment. As discussed above, in some embodiments, the container only contains a multilayered article, and in such cases, the multilayered article covers 100% of the wall of the container by area. In some embodiments, the multilayered article covers greater than or equal to 10%, greater than or equal to 20%, greater than or equal to 30%, greater than or equal to 40%, greater than or equal to 50%, greater than or equal to 60%, greater than or equal to 70%, greater than or equal to 80%, or greater than or equal to 90% of the wall of the container by area. In some embodiments, the multilayered article covers less than or equal to 100%, less than or equal to 90%, less than or equal to 80%, less than or equal to 70%, less than or equal to 60%, less than or equal to 50%, less than or equal to 40%, less than or equal to 30%, or less than or equal to 20% of the wall of the container by area. Combinations of these ranges are also possible (e.g., greater than or equal to 10% and less than or equal to 100%, greater than or equal to 20% and less than or equal to 100%, or greater than or equal to 20% and less than or equal to 80%). Other ranges, both higher and lower than those described above, are also possible, as the disclosure is not so limited.

[0197] In some aspects, the disclosure relates to methods of making a container using an article provided herein. Any of a variety of suitable methods may be used to make the article into the container. For example, in some embodiments, the method comprises folding the article into the shape of the container. Other methods may also be used to shape the container. For example, in some embodiments the container may be molded, bent, folded, stamped or cut to shape the container. In some embodiments, the method comprises sealing a sealant layer of the multilayered article to itself (or to another multilayered article), e.g., to form a pouch or sleeve.

[0198] An advantage of methods provided herein is that they avoid using a multi-step batch approach, according to one set of embodiments. This reduces the need for separate steps of loading / unloading a roll of packaging material into a vacuum chamber, in some embodiments. Such steps are costly (e.g., vacuum equipment is expensive), slow (e.g., time is required to pump the chamber down to vacuum), and / or create material waste (e.g., the ends of the roll are not coated) in at least some cases.

[0199] Spatial atomic layer deposition (SALD) is an open-air vapor-phase deposition technique. A coating head may be used to deliver one or more chemical precursors that react with other chemical precursors and / or decompose due to an external energy source (e.g., thermal, laser, plasma), resulting in the deposition of a desired material on a surface. A variety of gas channels may be present, including those to deliver the chemical precursors, shielding gas(es), energy sources, and / or exhaust channels to remove reaction products, as illustrated in FIG. 8. A substrate may be moved relative to a coating head, such as in one direction or in oscillation.

[0200] With reference to FIG. 8, the barrier coatings 102 discussed herein may be deposited onto a substate using SALD. An example SALD process generally includes ejecting working gas (e.g., precursor gas, reactant gas, inert gas, etc.) via one or more slits 600 and withdrawing exhaust gas via one or more slits 602, in which the slits 600, 602 communicate the gas with a network of channels within a structure that may be termed a SALD coater or head. This reduces or eliminates the need for evacuation and purge steps that make traditional ALD slow, such that SALD can be one to two orders of magnitude faster than conventional ALD. SALD can produce ultra-thin coatings of materials (e.g. metal oxides) that are compact, conformal, and pinhole-free and can deposit the coatings under open-air conditions and pressures, and at room or low temperatures, without the need for a vacuum chamber. SALD is scalable and compatible with roll-to-roll manufacturing and has been demonstrated to work on variety of surfaces including, but not limited to, plastics and paper. More information on ALD and SALD can be found in PCT publication WO2021119829, entitled “Apparatus and Method for Thin Film Deposition”, filed on December 18, 2020, which is incorporated herein by reference.

[0201] The present disclosure relates, according to one set of embodiments, to an atomic layer deposition (SALD) head and an apparatus incorporating multiple SALD heads for providing gas to a substrate. The SALD head includes a permeable material disposed between the input and output faces to ensure even gas distribution across the head's width. The permeable material can be a particulate, lattice structure, mesh, or porous media, with options including stainless steel balls, glass beads, fiberglass, and more. The permeable material may also exhibit a density gradient and be contained in a removable insert with segmented materials that control gas flow. This design enhances deposition uniformity and process control in atomic layer deposition applications on substrates.

[0202] Disclosed herein is an apparatus and method for high-throughput deposition of ultra-thin functional coatings on flexible materials in open air without a vacuum chamber, where the coating is comprised of one or more layers. The disclosed apparatus uses a gas delivery system to deliver one or more precursor gases to each of one or more spatial atomic layer deposition (SALD) coaters, and a system of rollers and heaters to transport the flexible material past the coaters, according to one set of embodiments.

[0203] FIG. 9 is a non-limiting schematic of an embodiment of the disclosed spatial atomic layer deposition (SALD) apparatus, according to one set of embodiments. Illustrated in FIG. 9 are the key components including, but not limited to, at least one SALD coater, a system of rollers, heaters, vessels containing precursor and reactant chemicals, mass flow controllers, on-off valves, and gas lines that connect the different components. The configuration and arrangement of the components in FIG. 9 represent one embodiment of the disclosed apparatus; the components can have different configurations and arrangements.

[0204] According to FIG. 9, the lines (e.g., stainless steel tubes or Teflon™ tubes) and components upstream of the coater, which include one or more inert gas tanks, chemicalcontaining vessels (e.g., bubblers), mass flow controllers and on-off valves constitute the gas delivery system of the disclosed apparatus. The gas delivery system serves the purpose of delivering one or more precursor gases, one or more reactant gases, and inert gas to each of one or more SALD coaters. One or more inert gas sources (e.g., storage tank) supplies inert, non-reactive gas to one of more SALD coaters and may also be used to carry precursor and / or reactant gases to the coater(s). The pressure of the inert gas may be regulated by one or more pressure regulators. The precursor and reactant gases may be generated by techniques such as, but not limited to, bubbling a liquid chemical with the inert gas, nebulizing a liquid chemical, by heating a liquid or solid chemical, or a combination thereof. The precursor and reactant gases may additionally or alternatively be generated by techniques such as, but not limited to, direct liquid injection where a liquid chemical precursor is introduced to a vaporizer which vaporizes the liquid and ejects gas out of a nozzle, or a combination thereof. The chemical vapors may also be supplied in the gaseous state from a storage tank, or generated by another device, such as an ozone generator. The flow rates of the inert gas, one or more precursor gases, and one or more reactant gases are controlled by mass flow controllers and on-off valves, such as manual diaphragm valves or pneumatic valves, according to one set of embodiments, where the valves can be opened or closed. The flow controllers and valves may be controlled manually or remotely using a control system.

[0205] Illustrated in FIG. 9, one or more SALD coaters serve the purpose of delivering the precursor, reactant, and inert gases onto the flexible substrate material. The coater comprises multiple internal gas channels that redirect and distribute the gases out onto the flexible material in an appropriate arrangement to result in SALD, as illustrated in FIG. 8. Other components may be integrated into one or more SALD coaters, including, but not limited to, cooling and heating elements and plasma sources. For example, one or more plasma sources may be embedded into the coater to lower the temperature for the coating deposition. According to FIG. 9, one or more exhaust pumps are connected to the coater. They serve the purpose of removing gases such as unreacted precursor, reactant, and inert gases from the space between the surface of the coater and the surface of the flexible material.

[0206] Illustrated in FIG. 9, an optional heater may serve the purpose of heating up the flexible material to facilitate chemical reactions on the surface of the flexible material. In the embodiment shown in FIG. 9, the spatial ALD configuration comprises one horizontal heater spanning the length of the coater. The configuration can comprise of multiple sets of heaters with different heating power and with different shapes and sizes (e.g. a drum heater that the flexible material wraps around). Additionally, one or more heaters may be embedded into the coater. One or more heaters may also be used to control the position of the surface of the flexible material relative to one or more of the SALD coaters, based on the mechanical positioning of the heater(s).

[0207] One embodiment of the disclosed apparatus includes a web system to move a roll of flexible material past one or more SALD coaters. One embodiment of the web system is Illustrated in FIG. 9. It comprises an arrangement of rollers, which may include, but is not limited to, winders, unwinders, nip rollers, load cells, web guides, idlers, and dancers. One or more of the rollers may be heated to control the temperature of the flexible material. The mechanical positioning of the rollers may be used to position flexible material relative to one or more SALD coaters and may be used to control the distance between the surface of the flexible material and the surface of the SALD coater.

[0208] In another embodiment of the disclosed apparatus, a sheet or multiple sheets of flexible material can be mounted on a translating stage which moves past the coater either in a single-direction or in both directions for the coating process. The translating stage may be heated and may be used to control the distance between the surface of the flexible material and the surface of the SALD coater.

[0209] More information on possible embodiments of the gas delivery system, SALD coater(s), exhaust pump(s), heater(s), and translating stage can be found in PCT publication WO2021119829, entitled “Apparatus and Method for Thin Film Deposition”, filed on December 18, 2020 which is herein incorporated by reference.

[0210] SALD coaters can be positioned to coat one or more sides of the flexible material. FIGS. 10A-10B show two examples of how the SALD coaters can be positioned relative to the surfaces of the flexible material. In at least one embodiment, all the SALD coaters are positioned to coat the same surface of the flexible material. In another embodiment of the disclosed apparatus, one or more of the SALD coaters are positioned to coat the opposing surfaces of the flexible material.

[0211] In one embodiment of the disclosed apparatus, other equipment may be located adjacent to one or more SALD coaters to allow characterization or modification of the flexible material or characterization or modification of the different layers of the ultra- thin coating. FIG. 11 illustrates one embodiment of the disclosed apparatus, where one piece of equipment is located adjacent to the first SALD coater and a second piece of equipment is located between the second and third SALD coaters, such that the flexible material travelling in one direction from the unwinder to winder travels past the first piece of equipment before being coated by the first coater and travels past the second piece of equipment after being coated by the first and second coaters but before being coated by the third coater. Examples of equipment that could be placed adjacent to the SALD coaters include, but are not limited to, web cleaning instruments (e.g., compressed air and exhaust to clear dust, deionizers), one or more plasma sources to clean or modify the surface energy of the surface of the flexible material for better coating adhesion, one or more plasma sources to clean the coated layers, one or more ellipsometers to characterize the coated layers, or one or more reflectance spectrometers to characterize the coated layers, and one or more quality assurance or quality control instruments to monitor the reliability of the coating process.

[0212] The disclosed apparatus may be a stand-alone system or a drop-in system that is integrated into a manufacturing line. FIG. 12 illustrates these two embodiments of the disclosed apparatus. In the standalone embodiment, all components of the disclosed apparatus are contained within a cabinet, with external connections including, but not limited to, power, gases, and exhaust, and the functional coatings are produced on flexible materials loaded into the cabinet. In the drop-in embodiment, one or more SALD coaters from the disclosed apparatus are placed into a manufacturing line, and the other components of the disclosed apparatus (gas delivery system, exhaust pump(s), heater(s), etc.) may also be located within the manufacturing line or may be placed in proximity to the manufacturing line, with suitable connections between the different components. Referring again to FIG. 8, it is seen that the drop-in embodiment of the disclosed apparatus can eliminate the need for a separate, batch, barrier-coating process in the flexible-packaging manufacturing process.

[0213] The internal gas channels in the SALD coater(s) may be modular in nature. The gas channels can be arranged such that a flexible material moving next to the reactor is sequentially exposed to precursor and reactor chemicals, resulting in SALD, as illustrated in FIG. 8. One or more SALD coaters can have different numbers of modular gas channels to allow deposition of different layer thicknesses and different precursor and / or reactant chemicals may be delivered by the gas delivery system to different gas channels so that different materials can be deposited, allowing multi-layer coatings, but not limited to the stated. FIG. 13 shows one embodiment, where three different combinations of one or more precursor and reactant gases are delivered to different numbers of distinct gas channels in a SALD coater, which may result in the deposition of a functional coating comprised of three layers, each of which may be a different thickness and a different material. Other aspects may also be adjusted to control the thickness and composition of each layer deposited, including, but not limited to, the speed at which the flexible material is moved relative to the SALD coater and the flow rates of the gases from the gas channels

[0214] In one embodiment of the disclosed method, the flexible material travels in one direction relative to the SALD coaters. In another embodiment of the disclosed method, the direction of travel of the flexible material may vary to allow the deposition of thicker coatings or coatings with variable thicknesses. The rollers of the disclosed apparatus may allow the roll of flexible material to move in single direction relative to one or more SALD coaters or in both directions relative to one or more SALD coaters (i.e., rollers may act as both unwinders and winders). In one embodiment shown in FIG. 14A, the rollers are operated in a manner to move the flexible material in one direction at a constant speed relative to one SALD coater. In another embodiment shown in FIG. 14B, the rollers are operated in a manner to move the flexible material in both directions relative to one SALD coater, which may result in the deposition of thicker coatings on the flexible material (e.g., by oscillating the flexible material past the SALD coater). In another embodiment shown in FIG. 14C, the rollers are operated in a manner to move the flexible material in both directions relative to two SALD coaters, which may result in the deposition of thicker coatings on the flexible material (e.g., by oscillating the flexible material past the SALD coaters) and / or coatings with variable thickness and / or composition (e.g., by exposing different portions of the flexible material to the different coaters for different durations).

[0215] According to some embodiments, a substrate (e.g., a flexible material) is passed next to the coater or coaters to deposit one or more layers of an ultra-thin coating via SALD. The number of layers and the thickness of each layer that is deposited can be controlled by the number of SALD coaters, the design of each SALD coater, including, but not limited to, the number of gas delivery channels in the coater, and the selection of precursor gases that are delivered to each reactor, among other operating parameters of the apparatus.

[0216] The disclosed apparatus and method can be used to coat one or more surfaces of a flexible substrate material, which may have varying surface morphology, with one or more conformal, ultra-thin, functional coatings, where each coating is comprised of one or more layers of elemental or compound materials. The ultra-thin coating or coatings may perform one or more functions or may constitute a component of a device that is manufactured on the surface of the flexible material.

[0217] FIG. 15 shows an example spatial atomic layer deposition (SALD) apparatus 1500 operable to deposit a barrier coating 102. The apparatus 1500 includes a SALD head 1502, a conveyance system 1504, and a gas-delivery system 1506. A heater 1508 may be provided at the SALD head 1502. Any suitable number of SALD heads 1502 may be used to deliver any suitable combination of gases by the gas-delivery system 1506 to deposit a barrier coating 102 onto a substrate conveyed past the SALD head 1502 by the conveyance system 1504. The substrate may be conveyed in one or both directions past one or multiple SALD heads 1502 to build up the barrier coating 102.

[0218] The conveyance system 1504 may include rollers 1510, web guides 1512, nip rollers 1513, idlers 1514, dancers 1516, load cells 1518, and like components positioned between an unwinder 1520 and a winder 1522 to convey a substrate material 1524, such as a thin sheet or membrane of material (sometimes called a “film,” particularly in the packaging industry, but this is not to be confused with the thin film or coating being deposited). With the convenance system 1504, the substrate material 1524 may be unwound from a roll at the unwinder 1520, coated by the SALD head 1502, and wound onto another roll at the winder 1522. The positioning of the rollers may be used to position flexible material relative to one or more SALD heads 1502 and may be used to control the distance between the surface of the flexible material 1524 and the surface of the SALD head 1502. The gas-delivery system 1506 includes vessels 1530, 1532, 1534 with inert gas (e.g., nitrogen), precursor (e.g., trimethylaluminum, A1(CH3)3, for aluminum oxide), and reactant (e.g., an oxidant such as H2O), mass flow controllers 1536, on-off valves 1538, and gas lines 1540 that fluidly connect these components. Each gas line 1540 may deliver to the SALD head 1502 pure or a mixture of an inert gas, precursor, and reactant, at a flow rate controlled by respective mass flow controller(s) 1536 and on-off valve(s) 1538. The configuration and arrangement of the components in FIG. 15 represent an example. In other examples, the components may have different configurations and arrangements.

[0219] The gas lines 1540 may be tubes made of chemically stable or inert material, such as stainless steel or Teflon™ (polytetrafluoroethylene), connected between components upstream of the SALD head 1502. Such components may include an inert gas vessel 1530, chemical-containing vessels (e.g., bubblers) 1532, 1534, mass flow controllers 1536, and on-off valves 1538. This gas delivery system 1506 serves the purpose of delivering one or more precursor gases, one or more reactant gases, and one or more inert gases, in pure form or suitable mixtures, to the SALD head 1502. The inert gas vessel 1530 supplies inert, non-reactive gas to the SALD head 1502 and may also be used to carry precursor gas from a precursor gas vessel 1534 and / or reactant gas from a reactant gas vessel 1532 to the SALD head 1502. The precursor and reactant gases may be generated by techniques such as, but not limited to, bubbling a liquid chemical with the inert gas, nebulizing a liquid chemical, by heating a liquid or solid chemical, direct liquid injection where a liquid chemical precursor is introduced to a vaporizer which vaporizes the liquid and ejects gas out of a nozzle, or a combination thereof. Chemical vapors may also be supplied in the gaseous state from a storage tank, or generated by another device, such as an ozone generator, which may be used to generate a reactant gas. The flow rates of the inert gas, one or more precursor gases, and one or more reactant gases are controlled by mass flow controllers 1536 and on-off valves 1538, such as manual diaphragm valves or pneumatic valves. The flow controllers 1536 and valves 1538 may be controlled manually or electronically by a control system.

[0220] Illustrated in FIG. 15, one or more SALD heads 1502 deliver a precursor, reactant, and inert gas onto a substrate material 1524. The head 1502 comprises multiple intemal gas channels that redirect and distribute the gases out onto the flexible material 1524 in an appropriate arrangement to result in SALD, as illustrated in FIG. 8. The head 1502 includes any suitable number and configuration of slits 1550 to output gas to the substrate material 1524. Other components may be integrated into one or more SALD heads 1502, including, but not limited to, cooling and heating elements and plasma sources. For example, one or more plasma sources may be embedded into the head to lower the temperature for the coating deposition. According to FIG. 15, one or more exhaust pumps 1542 are connected to the head 1502. The exhaust pump 1542 removes gases such as unreacted precursor and / or reactant and inert gas from the space between the operating surface 1544 of the head 1502 and the surface of the flexible material 1524.

[0221] Illustrated in FIG. 15, the heater 1508 may be used to heat the flexible material 1524 to facilitate chemical reactions on the surface of the flexible material 1524. In the example shown, the heater 1508 spans the length of the head 1502. Various heaters with different heating power and with different shapes and sizes (e.g., a drum heater that the flexible material wraps around) may be provided. Additionally, one or more heaters may be embedded into the head 1502. One or more heaters may also be used to control the position of the surface of the flexible material relative to one or more of the SALD heads 1502, based on the mechanical positioning of the heater(s). One or more of the rollers of the conveyance system 1504 may be heated to control the temperature of the flexible material 1524.

[0222] In other examples, a sheet or multiple sheets of flexible material can be mounted on a translating stage which moves past the head either in a single-direction or in both directions for the coating process. The translating stage may be heated and may be used to control the distance between the surface of the flexible material and the surface of a SALD head 1502.

[0223] More information concerning examples of the gas delivery system, SALD head(s), exhaust pump(s), heater(s), and translating stage can be found in PCT publication WO2021119829.

[0224] With reference to the general SALD system of FIG. 15, various techniques are discussed herein to reduce the overall size and increase the overall efficiency of a continuous coating deposition system. It is contemplated that, in various implementations, tens or hundreds of individual SALD heads may be used to dispose a coating to a substrate. Compactness, modularity, maintainability, and efficiency are thus important considerations. Compactness in the direction of substrate movement is an important factor in reducing production line size. In a system with, for example, 500 SALD heads, reducing the space occupied by a single SALD head by 0.5 cm in the direction of substrate conveyance may reduce the overall size of the coating portion of the line by 2.5 m (500x0.005 m). This helps reduce the footprint of new line installations and also helps when retrofitting existing lines, according to one set of embodiments.

[0225] FIG. 16A shows an example apparatus 1600 that includes SALD heads 1602 arranged in a compact adjacent spatial relationship with respect to a conveyance subsystem 1602 that is configured to convey a substrate 1606 past the SALD heads 1602. The compact adjacent spatial relationship is configured to provide an even distribution of gas by the SALD heads 1602 to the substrate 1606.

[0226] The conveyance subsystem 1604 includes a cylindrical roller 1608 over which the substrate 1606 is conveyed. The roller 1608 may provide an air (or other gas, generally termed “air”) cushion subsystem to reduce risk of damaging the substrate 1606 or coating disposed thereon (e.g., the roller side of the substrate may be coated as well). Other components of the conveyance subsystem 1604, such as other rollers, may be air cushioned as well. Air cushioning reduces or eliminates direct contact of the substrate 1606 to the component to reduce or eliminate scratching, rubbing, or other damage to the substrate 1606. In other examples, other techniques may be used to reduce damage to the substrate 1606, such as a roller covering (e.g., silicone covering), a cork roller, a Teflon™ roller, a plasma-treated roller, and similar. In addition or alternatively, a roller, such as the roller 1608, may be driven at a speed that reduces or eliminates a differential in speed between the surface of the component and the substrate 1606. For example, the roller 1608 may be driven at a rotational speed that causes the linear speed of the surface of the roller 1608 to closely or exactly match the linear speed of the substrate 1606. This may also reduce or eliminate scratching or other damage to the substrate 1606.

[0227] The compact adjacent spatial relationship of SALD heads 1602 includes a circumferential arrangement of SALD heads 1602 around the roller 1608. The gas-output faces 1610 of the SALD heads 1602 are radially equidistant from the cylindrical surface of the roller 1608 to promote even and predictable deposition of barrier coating material.

[0228] FIG. 16B shows the SALD heads 1602 in greater detail. The gas-output faces 1610 of the SALD heads 1602 may be curved, shown at 1612, to match a curvature of the cylindrical surface of the roller 1608. This allows each slit 1614 in the gas-output face 1610 to be equidistant from the roller 1608.

[0229] Returning to FIG. 16A backing structure 1616 (partially shown) may be provided to support the SALD heads. The backing structure may be used as a datum to assist in precisely locating the SALD heads 1602. In various examples, the radial distance from the gas-output face 1610 to the substrate 1606 is 1 mm or less. Shims, adjustable plates positionable by set screws, a lead screw, servo motor, rail, springs, pneumatics, or similar mechanisms / structures may be used to fine-tune the position of a SALD head 1602.

[0230] The radial arrangement of SALD heads 1602 provides for compactness that may reduce the overall footprint of the machine.

[0231] The apparatus 1600 may include a positive pressure enclosure that surrounds the SALD heads 1602. Positive pressure may be provided by gas, such as nitrogen, that is used in the SALD process. Positive pressure may be relatively low. The apparatus 1600 may include a negative pressure enclosure that surrounds the SALD heads 1602. Negative pressure may be provided by a vacuum that reduces pressure within the enclosure relative to atmospheric pressure.

[0232] The apparatus 1600 may be implemented as a module. A modular apparatus may thus be formed of one or more apparatuses 1600. For example, a module implementation of the apparatus 1600 may include 100 SALD heads 1602 radially arranged around the roller 1608 to deposit a barrier coating with a total nominal thickness of 10 nm. Five such module implementations of the apparatus 1600 may be arranged on a line, so as to deposit a barrier coating with a total nominal thickness of 50 nm.

[0233] A measurement device may be provided to the apparatus 1600 to measure a thickness of a material of the barrier coating or a total thickness of the barrier coating. Measurement devices may be positioned at intervals between SALD heads 1602. Systems such as that depicted in FIG. 8 can generate powder that causes issues such as clogging. Chemical precursors may cause undesired reactions when they mix with atmospheric air and lead to spatial and temporal non-uniformities in the deposited material or coating. Precursors and / or reactant gases may interact with each other or other gasses outside of intended circumstances leading to undesirable reaction products. It is a challenge in the industry to maintain sufficient gas isolation to ensure that the coating can be properly deposited onto substrates without being affected by surrounding air and / or other gas(es) found in the process and / or apparatus. The clogging issue, reaction with atmospheric air, insufficient gas isolation, and unexpected reaction products may affect process control and often lead to poor coating properties such as non-uniform deposition, formation of pinholes and inconsistent performance. Hence, balancing the flow interaction among the chemical precursor, the shielding gas(es) and exhaust strength is effective in reducing powder formation.

[0234] According to an aspect of the present disclosure, a SALD system includes a coating head including a precursor gas channel configured to provide a precursor gas to a substrate, a reactant gas channel positioned forward of the precursor gas channel, where the reactant gas channel is configured to provide a reactant gas to the substrate, and a sequence of inert gas channels positioned with respect to the precursor gas channel and the reactant gas channel.

[0235] The sequence of inert gas channels may be positioned forward or rearward of the reactant gas channel and the precursor gas channel.

[0236] The sequence of inert gas channels may be positioned between the reactant gas channel and the precursor gas channel.

[0237] The SALD system may further include a body in which the precursor gas channel and the reactant gas channel are provided and a module in which the sequence of inert gas channels is provided. The module may be removably attachable to the body.

[0238] The coating head may further include a surface treatment at surface of the body of the coating head adjacent the substrate.

[0239] The SALD system may further include a first exhaust flow path connected to an exhaust channel of the coating head adjacent the precursor gas channel and a second exhaust flow path connected to another exhaust channel of the coating head adjacent the reactant gas channel.

[0240] The SALD system may further include a pressure gauge positioned at the first exhaust flow path or the second exhaust flow path. The pressure gauge may be configured to detect a blockage in the first exhaust flow path or the second exhaust flow path.

[0241] The SALD system may further include a pump positioned at the first exhaust flow path or the second exhaust flow path and a flow speed controller connected to the pump. The pump and flow speed controller may be configured to increase a flow rate of exhaust through the first exhaust flow path or the second exhaust flow path to clear a blockage.

[0242] The SALD system may further include an environmental control chamber in which the coating head is positioned. The environmental control chamber may be configured to control temperature, pressure, and humidity of a local environment around the coating head.

[0243] An end slit of the precursor gas channel, the reactant gas channel, or an exhaust channel may be offset from an end slit of an inert gas channel in a direction away from the substrate.

[0244] According to another aspect of the present disclosure, a SALD system includes a coating head including a precursor gas channel configured to provide a precursor gas to a substrate a reactant gas channel positioned forward of the precursor gas channel, where the reactant gas channel configured to provide a reactant gas to the substrate, and an alternating sequence of inert gas channels and exhaust channels positioned with respect to the precursor gas channel and the reactant gas channel. Some or all inert gas channels may be configured to provide an inert gas to the substrate to purge unwanted material from the substrate, according to one set of embodiments. For example, each inert gas channel is configured to provide an inert gas to the substrate to purge unwanted material from the substrate, according to one set of embodiments. Some or all exhaust channels may be configured to withdraw unwanted material from a vicinity of the substrate, according to one set of embodiments. For example, each exhaust channel is configured to withdraw unwanted material from a vicinity of the substrate, according to one set of embodiments.

[0245] The SALD system may further include, attached to the coating head, a surface treatment apparatus, a particulate monitoring device, an ultrasonic vibrator, a heater, a dehumidifier, a static charge generator, or a combination of such.

[0246] In order to commercialize open-air thin-film deposition techniques for mass production, processes need to be made reliable and effective without significant downtime. Exhaust channels may be connected to an exhaust system which includes one or multiple vacuum generating sources to remove the reaction products. Downtime may be caused by clogs in an exhaust channel and powder build-up under the coating head, inside the line, or on a substrate.

[0247] During the deposition process, airborne particulates from the surrounding environment can contaminate the material surfaces. Conventional vacuum-based deposition techniques require a vacuum chamber to remove air particles and contaminants. Alternatively, a cleanroom can be used to provide a well-isolated and controlled environment from contamination, but such facilities are very expensive to maintain and operate.

[0248] Conventional close-proximity SALD techniques include air-bearing (aircushioning) designs with a nitrogen environment between the substrate and reactor which may help with contaminant control. However, balancing air-bearing for precise gap and movement control is challenging and it also limits the type of substrate, especially its weights and geometries, that can be processed.

[0249] Disclosed herein are open-air deposition processes that may operate with or without a vacuum chamber or cleanroom, depending on the application. The reactor has continuous streams of inert gas(es) to purge airborne contamination and control the surface quality prior to deposition. The pressure and flow rates of the streams of inert gas(es) as well as exhaust can be actively controlled to isolate the deposition area under the coating head; by creating a sufficient outflow of inert gas(es) from the deposition area, inflow of surrounding air and contaminants is prevented. A particulate monitor may be installed to determine the particulate level near the deposition area. An air purifier may be used to reduce dust levels. These components create an isolated environment for coating reactions to occur on the substrate surface and keep contaminants out of the deposition area.

[0250] The precursor gas(es) may be highly reactive (e.g., pyrophoric). They may react instantly when exposed to air or another reactant. Hence, it may be imperative to prevent the precursors gas(es) from mixing and reacting inadvertently with each other or air, especially in the open-air process. During conventional atomic layer deposition (ALD) process, the precursor gas(es) are introduced one gas at a time in a vacuum chamber to prevent them, from mixing. This makes conventional ALD slow and difficult to scale up.

[0251] Instead of introducing the precursor gas(es) at different times, the techniques disclosed herein introduce gases at the same time and separate them spatially. Streams of inert gas(es) separate the precursor gas from mixing with either the surrounding air or the neighboring reactant gas(es). Despite the presence of streams of inert gas(es) on either side of the precursor channels, the relative motion of the substrate and coating head can result in air passing through these streams. Purging before and after the deposition area with one or more streams of inert gas(es) and one or more exhaust channels may be used to reduce the amount of surrounding air that is drawn into the deposition area.

[0252] A variety of factors, including, but not limited to, excessive chemical precursor gas(es), poorly isolated precursor gas(es), or airborne contamination may cause powder formation which may accumulate in various parts of the system, including under the coating head or in the exhaust channel. Powder build-up under the coating head may cause non-uniformity in the coating, may alter the properties of the resulting coating, or may partially or completely block gas output slits. Such powder may also contaminate surface cleanliness of the substrate and / or coating. On the other hand, powder build-up inside one or more channels may lead to clogging and affect the exhaust effectiveness and the deposition process. A precursor may also diffuse at the bottom face of the coating head made of plastic or similar material, which may cause clogging particularly at the channel output slits resulting in maintenance downtime to clear.

[0253] The techniques disclosed herein use various approaches to address powder buildup and maintain cleanliness of the coating head, such as reducing powder formation, redirecting an accumulation area, and using high suction. To reduce powder formation, a gas isolation system may be used to prevent the reaction of a chemical precursor with the surrounding air or neighboring precursors.

[0254] To prevent powder formation, a film-growth inhibitor may be applied to the surfaces of the apparatus (e.g., the bottom face of the coating head). This may include, for example, self-assembled monolayer chemicals that prevent the attachment of the chemical precursor molecules to the surface.

[0255] To monitor powder formation, pressure of the exhaust channel(s) may be monitored. The pressure of exhaust channel(s) increases when clogs build up and at certain pressure, suction will not be effective. Pressure and flow sensors may be integrated into the system to monitor powder buildup.

[0256] To address powder formation, inert gas(es) may be introduced into the exhaust channels to redirect the powder formation further downstream of the exhaust system.

[0257] High suction pressure from the exhaust system may also be used to remove powder buildup from the deposition area.

[0258] Excess chemical precursors that do not react on the substrate surface may cause unwanted chemical vapor deposition (CVD) reactions, leading to non-uniform coatings. They may also cause powder buildup and reduce precursor utilization. Powder buildup may clog system components including gas channels, manifolds, and filters and render them ineffective.

[0259] Deposition, as disclosed herein, is a self-limiting process and different sets of optimal deposition conditions for different materials are determined to reduce the amount of excess reactants. Excess reactants get removed through the exhaust channels within the coating head, which are connected to exhaust filters and exhaust pumps and monitored by one or more flow monitors. The exhaust filter may be a replacement filter with a large volume to collect powder and reduce buildup. The exhaust pump may be controlled to maintain exhaust flow rate at the desired level.

[0260] There may be two or more exhaust lines and it may be possible to switch the exhaust operation between the lines, so that a particular exhaust line may undergo maintenance and service while the system remains in operation.

[0261] In view of the above, it should be apparent that the techniques disclosed herein are useful for powder mitigation and exhaust management for thin film deposition. SALD, an open-air vapor-phase deposition technology, which may use a coating head with a variety of gas channels to deliver chemical precursors, shielding gas(es), and / or exhaust channels to remove reaction products, often generates powder that causes issues such fluid system blockage and poor coating properties due to challenges with proper gas isolation and powder mitigation. The techniques disclosed herein may be used to purge airborne particulates from the substrate surface undergoing the SALD process. The techniques may be used to treat and clean a substrate surface for improved coating properties. Furthermore, the techniques provide a controlled methodology to remove excess precursor chemical gas(es), unclog lines, and improve process reliability and uptime, according to one set of embodiments.

[0262] Discussed herein are example SALD apparatuses that include SALD heads arranged in a compact adjacent spatial relationship with respect to a conveyance subsystem that is configured to convey a substrate past the SALD heads. In various examples, the compact adjacent spatial relationship is configured to provide an even distribution of gas by the SALD heads to the substrate. The internals of SALD head may include configurable inserts, lattice structures, and porous materials to help evenly distribute gas. Various other improvements will also be discussed.

[0263] The SALD heads discussed herein may have a rigid monolithic construction. Rigid monolithic construction provides for stiffness that helps ensure proper coating. Various techniques are described herein to provide for an accommodate rigid monolithic construction. The SALD heads discussed herein may be 3D printed with post printing machining at the output face. Suitable 3D printers include multi-jet printing devices sold by 3D Systems™ (www.3dsystems.com). Suitable resin includes VisiJet™ HT-90 resin, which is useful due to its tolerance to 60 °C operational temperature that is expected for the SALD heads discussed herein. Other manufacturing techniques may be used, such as diffusion bonding, extrusion, sheet metal stamping, and gluing several base parts together.

[0264] FIG. 17 shows a cross-section of the SALD head 1702, according to one nonlimiting embodiment. The SALD head 1702 comprises an input face 1804 for receiving gas G from the gas lines and an output face 1808 for outputting gas onto the flexible material. Disposed between the input face 1804 and output face 1808 is a permeable material 1812, such that gas passing from the input face 1804 to the output face 1808 passes through the permeable material 1812. The permeable material 1812 generally has a first end 1814 proximal the input face 1804 and configured to receive gas via the input face 1804, and a second end 1818 opposite the first end 1814 and configured to transfer gas to the output face 1808. Generally, the permeable material 1812 slows the flow of gas through the SALD head 1702 which helps to evenly distribute gas from the output face 1808. This may be advantageous for distributing gas over large coating areas, without discontinuities.

[0265] The permeable material 1812 may comprise a mesh or lattice structure. The mesh or lattice structure may be 3D-printed, machined, etched, sintered, or any other method known in the art.

[0266] The permeable material 1812 may comprise a particulate including but not limited to stainless steel balls, glass beads, glass microspheres, fiberglass, cellulose, grains, sand, powders, granules, dust, crushed rock, crystals, metal shavings, pellets, and a combination thereof. In some examples, the particulate comprises particles having uniform sizes and shapes. In other examples, the particulate comprises particulates having a mixture of sizes and shapes.

[0267] The permeable material 1812 may comprise a porous media including but not limited to a ceramic, a polymer, a metal (such as porous aluminum), stainless steel wool, a sponge, paper, cardboard, and a filtration media. In specific, non-limiting examples, the porous media comprises a 3D-printed material with intentional gaps or holes. In other non-limiting examples, the porous media comprises stacked layers of porous sheets, such as paper or cardboard. It may be advantageous for the pores to be evenly sized and / or evenly distributed throughout the porous media.

[0268] The density of the permeable material 1812 may be selected according to the desired effect. In examples where the density is relatively high compared to the surrounding space for gas to flow in the SALD head 1702, the permeable material may primarily influence the pressure component of the mass flow rate of the gas. In examples where the density is relatively low compared to the surrounding space for gas to flow in the SALD head 1702, the permeable material may primarily influence the velocity component of the mass flow rate of the gas. Generally, particulate materials are high density, whereas mesh and lattice structures are typically low-density materials, however exceptions exist.

[0269] The density of the permeable material 1812 may be uniform or non-uniform. In examples where the density is non-uniform, the permeable material may be graded across the length, width, or height. The density of the permeable material 1812 is highest at the first end 1814 and lowest at the second end 1818, according to one set of embodiments. The density of the permeable material 1812 is highest at the second end 1818 where the particles are smallest and lowest at the first end 1814 where the particles are largest, according to one set of embodiments. A skilled person will understand that gradients are not particularly restricted to lattice and particulate materials and in other examples, a gradient may be achieved with a porous material or mesh. Furthermore, while the permeable material 1812 has been depicted with a lengthwise gradient extending from the first end 1814 to the second end 1818, the density may instead vary widthwise, with the gradient extending across the width of the SALD head 1702.

[0270] In the examples shown and described above, the permeable material 1812 extends across an internal width and length of the SALD head 1702, however the permeable material 1812 is not particularly limited. In some examples, the SALD head is segmented. One example of a segmented SALD head is shown in FIG. 18, which shows a cross-section of the SALD head 1702 according to one set of embodiments. In this embodiment, the internal width of the SALD head H is divided into a plurality of segments 2004a, 2004b, 2004c (referred to generally as “segment 2004” or collectively as “segments 2004”). At least one of the segments 2004 comprises the permeable material 1812. One of the segments 2004 may comprise a blocking material 2008 configured to block the flow of gas. In specific examples, the blocking material is impermeable to air. One of the segments 2004 may comprise a material to freely allow the flow of gas. In some examples, two or more of the segments 2004 comprise permeable materials 1812 with differing characteristics. For example, the segments may differ in structure, density, density gradient, or the like. Generally, the permeability of each segment varies, resulting in air flow that varies across the internal head width H.

[0271] In the example shown in FIG. 18, segment 2004b comprises the permeable material 1812, and the remaining segments 2004 comprise the blocking material. As a result of the blocking area, a selective area of a flexible article is coated with the precursor gas, as defined by the coating width C of the SALD head 1702. The coating width C is less than the internal head width H. This arrangement is suitable for coating an area that is narrower than the internal head width H of the SALD apparatus 100. In a specific, non-limiting example, the internal head width H is 1 meter, and the coating width C is 0.6 meters.

[0272] Another way to control the coating width C is with inert gases. As shown in FIG. 19A, more than one gas is provided to the SALD head 1702 via the gas lines. The SALD head 1702 may further include gas channels arranged to direct the more than one gas to a respective portion of the porous media 1812. In this example, a precursor gas G-l is directed through the middle of the porous media 1812 and an inert gas G-2 is directed through the outer portions of the porous media 1812. Consequently, the precursor gas is applied only to the coating width C of the substrate. Furthermore, the inert gas G-2 can prevent the precursor gas from mixing with air, allowing the SALD head 1702 to be used in environments other than vacuum chambers. To improve control over the coating width C and prevent the precursor gas G-l from spreading, the inert gas G-2 may be delivered at a higher air pressure and / or flow rate as compared to the precursor gas G-L

[0273] Control over the coating width C may be further improved by segmenting the permeable material. FIG. 19B is a cross-section of the SALD head 1702 according to another embodiment. The segments 2004 comprise more than one type of permeable material 1812. In particular, segments 2004a and 2004c comprise a first permeable material 1812b and segment 2004b comprises a second permeable material 1812a. Like FIG. 19A, more than one gas is provided to the SALD head 1702 via the gas lines. The permeable materials may be selected to control the flow rate of each gas. In particular examples, the first permeable material 1812b has a lower density than the second permeable material 1812a, which increases the flow rate of the inert gas G-2 and limits the unintended spread of precursor gas G-L The pressure of the inert and precursor gases may be further controlled to more precisely control the coating width C.

[0274] The SALD head 1702 may include any suitable number of segments 2004. FIG. 20 is a cross-section of another example of a segmented SALD head. In this example, the SALD head includes 5 segments. The inert gas G-2 can prevent mixing between precursor gases G-l delivered through different segments of the SALD head 1702 and can further prevent mixing between the precursor gas G-l and other gases delivered by the SALD head such as reactant or co-reactant gases. A skilled person will now understand that any suitable number of segments may be included in the SALD head, and that the segments may be selected according to the desired properties of the coating.

[0275] The permeable material 1812 may be housed in a removable insert. In embodiments where the SALD head 1702 is segmented, the segments 2004 may be further housed in the insert. Generally, the insert is selected according to the desired air flow characteristics and coating width. The selected insert is inserted into a corresponding chamber in the SALD head 1702. The inserts improve the ease of maintaining and cleaning the SALD head 1702, as the insert may be cleaned and replaced or exchanged with a fresh insert. Removing and replacing an insert is also less likely to disturb the precise positioning of the output face of the SALD head 1702. It should be understood that any of the permeable materials 1812 described above may be provided in a removable insert.

[0276] The SALD head 1702 may comprise one or more corresponding chambers for receiving a plurality of inserts. In embodiments where the SALD head 1702 is configured to receive a plurality of inserts, various combinations of inserts may be inserted to control the characteristics of the gas flow. FIG. 21 is a cross-section of the SALD head 1702 according to one set of embodiments having a plurality of inserts 2204. In this embodiment, three inserts 2204 are inserted in the SALD head 1702, however the SALD head 1702 is not particularly limited, and the SALD head 1702 may be configured to receive any suitable number of inserts 2204. The inserts 2204 shown in FIG. 21 include segments of the blocking material 2008 surrounding the permeable material 1812, such that gas flows through the effective coating width C. Each of the inserts 2204 shown in FIG. 21 has congruent segments, according to one set of embodiments, however the inserts 2204 are not particularly limited. In other examples, such as the example shown in FIG. 22, the inserts 2204 have varying configurations. FIG. 22 is a cross-section of the SALD head 1702 according to another embodiment. In this embodiment, two of the inserts 2204 are unsegmented and comprise only the permeable material 1812, while the third insert 2204 is segmented with the blocking material 2008. Consequently, gas is funneled through the coating width C.

[0277] The shape of the insert 2204 is not particularly limited. Likewise, an SALD head may include an output slit in the output face for transmitting the gas to the substrate material, and the shape and dimensions of the output slit are not particularly limited. For example, output slits may be symmetrical or non-symmetrical. In some embodiments, output slits are rectangular, bi-concave, biconvex, hourglass -shaped, or bowtie shaped, and each type of slit may have advantages for SALD, depending on the context. A biconcave output slit with curvature that narrows towards the middle may be useful to encourage gas to exit the slit towards the ends. A biconvex gas output slit with curvature that narrows towards the ends, may be useful to encourage gas to exit the output slit towards the middle. A bowtie-shaped gas output slit with a linear shape that narrows towards the middle, may be useful to encourage gas to exit the slit towards the ends. An hourglass- shaped output slit with curvature that narrows towards the middle, may be useful to encourage gas to exit the output slit towards the ends. Generally, a widened region of the output slit may encourage gas to exit the slit at that region by way of reduced flow resistance. Such a widened region may be placed at a location expected to have reduced gas flow due to internal structure of the head, manifold, flow paths, etc. Numerous other examples of such output slits are contemplated.

[0278] Non-rectangular output slits may promote even flow of gas with respect to a length of the SALD head. The output slit may be wider at its ends to reduce resistance to flow at the ends, thereby encouraging flow to the ends which may otherwise receive insufficient amounts of gas.

[0279] The shape and dimensions of the output slit may be modified with a detachable slit plate. Non-limiting examples of attachment means include fasteners, welding, adhesive bonding, brazing, interference fit, threading, clamping, soldering, and combinations thereof.

[0280] Thus, the air flow in the SALD head 1702 can be controlled either with the permeable material 1812, an output slit, or a combination thereof.

[0281] One advantage of the methods of making multilayered articles provided herein is that, according to one set of embodiments, they can be integrated modularly with other processes for making multilayered articles. For example, SALD may be used in combination with in-line printing techniques, lamination techniques, and / or extrusion techniques to make articles useful for packaging. A variety of such methods are detailed below.

[0282] The disclosure, in some embodiments, relates to systems and apparatuses for making multilayered articles and / or packaging materials. According to an aspect of the present disclosure, an apparatus includes a first conveyance subsystem to transport a first substrate along a first path, a printer positioned on the first path to apply a marking to the first substrate, a dryer positioned on the first path downstream of the printer to dry the marking applied to the first substrate by the printer, and a second conveyance subsystem to transport a second substrate material along a second path. The apparatus further includes a spatial atomic layer deposition (SALD) head positioned on the first path or the second path and connectable to a gas-delivery subsystem to deliver gas to a respective one of the first substrate and the second substrate to form a barrier coating thereon.

[0283] The SALD head may be positioned on the first path downstream of the dryer.

[0284] The SALD head may be positioned on the first path upstream of the printer.

[0285] The SALD head may be positioned on the second path.

[0286] The first conveyance subsystem and the second conveyance subsystem may be arranged to merge the first path and the second path at a junction to form a third path along which the first substrate and second substrate are transported.

[0287] The apparatus may further include an extrusion coater positioned upstream of the junction to coat the first substrate or the second substrate with an adhesive to bond the first substrate and the second substrate.

[0288] The SALD head may form the barrier coating as an arrangement of alternating layers of different materials.

[0289] The apparatus may further include an air jet device positioned adjacent the SALD head to jet air or other gas at the respective one of the first substrate and the second substrate.

[0290] According to another aspect of the present disclosure, an apparatus includes a conveyance subsystem to transport a substrate along a path, a pre-coat subsystem positioned on the path to apply a pre-coat to the substrate to form a pre-coated substrate, a spatial atomic layer deposition (SALD) head positioned on the path downstream of the pre-coat subsystem and connectable to a gas-delivery subsystem to deliver gas to the precoated substrate to form a barrier coating thereon, and a top-coat subsystem positioned on the path downstream of the SALD head to apply a top coat to the barrier coating formed on the pre-coated substrate to form a flexible packaging film.

[0291] The apparatus may further include a dryer positioned on the path between the pre-coat subsystem and the SALD head to dry the pre-coated substrate.

[0292] The apparatus may further include a dryer positioned on the path downstream of the topcoat subsystem to dry the top coat.

[0293] The SALD head may form the barrier coating with an arrangement of alternating layers of different materials.

[0294] The top-coat subsystem may apply a heat sealable material as the top coat.

[0295] The apparatus may further include an air jet device positioned adjacent the SALD head to jet air or other gas at the pre-coated substrate.

[0296] According to another aspect of the present disclosure, an apparatus includes a first conveyance subsystem to transport a first substrate along a first path and a second conveyance subsystem to transport a second substrate material along a second path. The first conveyance subsystem and the second conveyance subsystem are arranged to merge the first path and the second path at a junction to form a third path along which the first substrate and second substrate are transported. The apparatus further includes an extrusion coater positioned upstream of the junction to coat the first substrate or the second substrate with an adhesive to bond the first substrate and the second substrate. The apparatus further includes a spatial atomic layer deposition (SALD) head positioned on the first path or the second path and connectable to a gas-delivery subsystem to deliver gas to a respective one of the first substrate and the second substrate to form a barrier coating thereon.

[0297] The apparatus may further include an air jet device positioned adjacent the SALD head to jet air or other gas at the respective one of the first substrate and the second substrate.

[0298] The present disclosure relates, in some embodiments, to integration of spatial atomic layer deposition (SALD) coating heads with related components to achieve continuous or roll-to-roll production of coated films. Such integrations are made possible or made more efficient because the SALD heads discussed herein are open-air and are not required to be located within a vacuum chamber. Moreover, various coatings discussed herein are stable immediately or shortly after deposition, which also helps facilitate beneficial integrations. One advantage of such integrations is increased throughput, which reduces the time and cost in application SALD coatings.

[0299] FIG. 23 shows an example apparatus 2300 that includes a spatial atomic layer deposition (SALD) head 2302 configured to deposit a barrier coating onto a substrate 2306, 2308 to form a film 2310.

[0300] The film 2310 may be used for packaging, such as food packaging (e.g., sealed bags or packages that contain food or ingredients,), beverages, home care products, personal care products (e.g., creams, lotions, gels, etc.), pharmaceuticals, sterile medical products or instruments, agricultural products, and similar products that benefit from protection against degradation or contamination and / or that require a relatively long shelf life. The substrate 2306, 2308 provides mechanical strength to the film 2310 and the barrier coating provides a barrier against material (e.g., oxygen, water, gases, particles, contaminates, etc.) that may otherwise pass into or through the substrate 2306, 2308.

[0301] Packaging is a suitable application for the techniques discussed herein but is not the only application. As such, the present disclosure is not limited to packaging film. It should be apparent that the teachings and examples provided herein as related to packaging film may be used for or readily adapted to other applications.

[0302] The apparatus 2300 is configured to merge multiple substrates 2306, 2308 to form the film 2310 by way of adhesive or other bonding technique. Accordingly, a SALD head 2302 may be provided to any of the transport paths 2312, 2314 used to convey a substrate 2306, 2308 to the point of merging.

[0303] The apparatus 2300 includes a first conveyance subsystem 2316 to transport a first substrate 2306 along a first path 2312. The first conveyance subsystem 2316 may include a roller, a web guide, a nip roller, an idler, a dancer, a load cell, and similar components to convey the substrate 2306. The first conveyance subsystem 2316 may receive the first substrate 2306 from an upstream component, such as an unwinder that provides a roll of substrate material. The apparatus 2300 further includes a printer 2318 positioned on the first path 2312 to apply a marking to the first substrate 2306 as the first substrate 2306 is conveyed along the first path 2312. Markings may include text, imagery, labels, logos, artwork, and other markings typically provided to packaging. The markings may be selectively deposited on the first substrate 2306 and need not cover the entire first substrate 2306.

[0304] The apparatus 2300 further includes a dryer 2320 positioned on the first path 2312 at a location downstream of the printer 2318. The dryer 2320 dries the marking applied to the first substrate by the printer 2318.

[0305] The apparatus 2300 includes a second conveyance subsystem 2322 to transport a second substrate 2308 along a second path 2314. The second conveyance subsystem 2322 may include a roller, a web guide, a nip roller, an idler, a dancer, a load cell, and similar components to convey the substrate 2308. The second conveyance subsystem 2322 may receive the second substrate 2308 from an upstream component, such as an unwinder that provides a roll of substrate material.

[0306] The first conveyance subsystem 2316 and the second conveyance subsystem 2322 may be arranged to merge the first path 2312 and the second path 2314 at a junction 2324 to form a third path 2326 along which the first substrate 2306 and second substrate 2308 are transported. The junction 2324 may be defined by a third conveyance subsystem 2328, which may include rollers or other components (see the first and second conveyance subsystems).

[0307] The apparatus may further include an extrusion coater 2330 positioned upstream of the junction 2324 to coat the first substrate 2306 or the second substrate 2308 with an adhesive 2332 to bond the first substrate 2306 and the second substrate 2308 together. The adhesive 2332 may take the form of a film or membrane may be a bulk material (e.g., liquid, gel, spray, etc.) that is applied to one or both substrates 2306, 2308. The first substrate 2306, the second substrate 2308, and the adhesive 2332 merge at the junction 2324. The substrates 2306, 2308 sandwich the adhesive 2332 to form the film 2310.

[0308] The extrusion coater 2330 may be configured to apply the adhesive 2332 or similar material using a solvent-based process, solventless process, extrusion lamination, and similar processes. A SALD head 2302 is positioned on the first path 2312 or the second path 2314. As discussed above, any suitable number of SALD heads 2302 may be provided to either or both paths 2312, 2314. The SALD head 2302 is connectable to a gas-delivery subsystem 2334 to deliver gas to the first substrate 2306 or the second substrate 2308, as the case may be, to form a barrier coating thereon. When more than one SALD head 2302 is used, each SALD head 2302 may be connected to its own gas-delivery subsystem 2334 or several SALD heads may be connected to a common gas-delivery subsystem 2334. A SALD head 2302 may be configured to deposit one layer of a coating, multiple layers of a coating, or all the layers of a coating. When a SALD head 2302 is configured to deposit fewer than all layers of a coating, more than one SALD head 2302 may be used and, for example, may be positioned adjacent one another.

[0309] A method of operation includes the first conveyance subsystem 2316 transporting the first substrate 2306 along the first path 2312 and the second conveyance subsystem 2322 transporting the second substrate 2308 along the second path 2314, with the two substrates 2306, 2308 meeting at the junction 2324. The printer 2318 prints ink or other marking material onto the first substrate 2306 to form an ink layer and the dryer 2320 dries the ink layer. The SALD head 2302 takes gas from the gas-delivery subsystem 2334 and applies a barrier coating to the first substrate 2306 or the second substrate 2308. If positioned to apply the barrier coating to the first substrate 2306, the SALD head 2302 may apply the barrier coating above or below the ink layer. The first substrate 2306 and the second substrate 2308 are brought together at the junction 2324 and bonded together, which may include the introduction of an adhesive 2332 by an extrusion coater 2330, to form a film 2310.

[0310] In other examples, in addition to or as an alternative to the subsystem formed by the printer 2318 and dryer 2320, the apparatus 2300 may include a lamination subsystem, a slitting subsystem, a cast film subsystem, a blown film subsystem, or similar subsystems for processing film.

[0311] Features and aspects of the apparatus 2300 may be combined with other features and aspects of the other apparatuses discussed herein. Like terminology and like reference numerals denote like components which may be added to the apparatus 2300 or used to replace component(s) of the apparatus 2300. FIG. 24 shows another example apparatus 2400 to manufacture a film 2402 with a barrier coating using a SALD head 2302. In this example, the SALD head 2302 is positioned downstream of a dryer 2320 that is downstream of a printer 2318, so as to apply the barrier coating to a first substrate 2306 that includes printed and dried marking material. In addition to drying marking material deposited by the printer 2318, the dryer 2320 may also help warm the substrate 2306 to aid deposition of the barrier coating. For details concerning the other components of the apparatus 2400, the above description related to FIG. 23 may be referenced.

[0312] The apparatus 2400 makes a film 2402 that has the following layers in order: first substrate, ink layer, barrier coating, adhesive, and second substrate. The term “substrate” is intended to refer to substrate material that has not yet been processed by the apparatus 2400. A substrate may have one or multiple layers of the same material or different materials. The term “substrate” is intended to refer to a substrate that may have had some processing performed by the apparatus 2400, such as the application of ink.

[0313] Features and aspects of the apparatus 2400 may be combined with other features and aspects of the other apparatuses discussed herein. Like terminology and like reference numerals denote like components which may be added to the apparatus 2400 or used to replace component(s) of the apparatus 2400. For example, in some embodiments, the SALD head 2302 may be positioned upstream of a printer 2318, so as to apply the barrier coating to a first substrate 2306 that does not yet include printed and dried marking material. The barrier coating would thus be positioned under an ink layer. Such an approach can, in some embodiments, produce a film that has the following layers in order: first substrate, barrier coating, ink layer, adhesive, and second substrate.

[0314] As another example, the SALD head 2302 may be positioned along a material path 2314 different from a material path 2312 that contains a printer 2318 and dryer 2320, so as to apply the barrier coating to a second substrate 2308 that does not receive marking material. As yet another example, in some embodiments the printer and dryer are not used, e.g., such that a film comprising, in order, a first substrate, a barrier coating, an adhesive, and a second substrate is produced. FIG. 25 shows another example apparatus 2500 to manufacture a film 2502 with a barrier coating using a SALD head 2302. In the example, the SALD head 2302 is positioned between a pre-coat subsystem 2504 and a top-coat subsystem 2506.

[0315] The apparatus 2500 includes a conveyance subsystem 2508 to transport a substrate 2510 along a path 2512. For details concerning the conveyance subsystem 2508, the above description related to conveyance subsystems 2316, 2322 of FIG. 23 may be referenced.

[0316] The apparatus 2500 further includes a pre-coat subsystem 2504 positioned on the path 2512 to apply a pre-coat to the substrate 2510 to form a pre-coated substrate. A precoat may be referred to as a primer.

[0317] The apparatus 2500 further includes a SALD head 2302 positioned on the path 2512 downstream of the pre-coat subsystem 2504 and connectable to a gas-delivery subsystem 2334 to deliver gas to the pre-coated substrate to form a barrier coating thereon. For detail concerning the SALD head 2302 and gas-delivery subsystem 2334, the above description related to FIG. 23 may be referenced.

[0318] The apparatus 2500 further includes a top-coat subsystem 2506 positioned on the path 2512 downstream of the SALD head 2302 to apply a top coat to the barrier coating formed on the precoated substrate, so as to form a flexible packaging film 2502. A heat sealable material may be used as the top coat, so as to aid the making of packages with the film 2502. In other examples, other top coat materials may be additionally or alternatively used to provide different useful structures and functions. A top coat may protect the barrier coating and further improve the barrier function of the film 2502 as a whole, for example, by improving the water vapor transmission rate (WVTR). For instance, a top coat material such as polyethylene may provide for heat sealing and improve the WVTR of the film 2502.

[0319] The apparatus 2500 may further include a dryer 2514 positioned on the path 2512 between the pre-coat subsystem 2504 and the SALD head 2302 to dry the pre-coated substrate prior to deposition of the barrier coating. In addition to drying pre-coat material applied by the precoat subsystem 2504, the dryer 2514 may also help warm the substrate 2510 to aid deposition of the barrier coating. The apparatus 2500 may further include a dryer 2516 positioned on the path 2512 downstream of the top-coat subsystem 2506 to dry the top coat after application of the top coat over the barrier coating.

[0320] The apparatus 2500 makes a film 2502 that has the following layers in order: substrate, pre-coat, barrier coating, and top coat. It should, of course, be understood that other layer and coating configurations are possible depending on the apparatus design, and that film 2502 should be understood to be a non-limiting embodiment, just like apparatus 2500.

[0321] Features and aspects of the apparatus 2500 may be combined with other features and aspects of the other apparatuses discussed herein. Like terminology and like reference numerals denote like components which may be added to the apparatus 2500 or used to replace component(s) of the apparatus 2500.

[0322] The above example arrangements are not intended to be limiting. In various other examples, the techniques discussed herein may be used to manufacture films with similar structures, such as, a substrate with a pre-coat and a barrier coating or a substrate with a barrier coating and a top coat. To achieve these examples, the respective top-coat or precoat subsystem may be omitted or deactivated. This applies to any of the other examples herein. The example arrangements described may omit one or more layers by omitted or turning off the respective component(s).

[0323] Example materials for the pre-coat include PVOH, EVOH, acrylic, polyurethane (PU), nanocellulose / micro fibrillated cellulose, PLA coating, PE coating, clay, or similar.

[0324] Example top coat materials include a PE layer for heat sealing and other materials discussed above as useful for the pre-coat.

[0325] Inline surface treatment may be used to help remove dust and particles to improve surface cleanliness and prevent pinhole formation. Example surface treatments (also termed pretreatment) include corona treatment, plasma treatment (e.g., argon plasma), and flame treatment. Pretreating the surface prior to applying the barrier coating may help with coating deposition by, for example, smoothing the surface in a way that improves the bonding of the coating. The barrier coating may conformally coat the surface and encapsulate any dust particles and thus surface treatment may be used but is not expected to be required in many cases. A substrate may include any one or combination of a skin layer, primer (pre-coat) layer, and pretreatment, on one or both sides.

[0326] In some embodiments, a system or apparatus comprises one or more quality control systems. A measurement device may be provided to the apparatus to measure a thickness of a material of the barrier coating or a total thickness of the barrier coating. A measurement device may be positioned downstream of the SALD head. When multiple SALD heads are used, measurement devices may be positioned at intervals between SALD heads. FIG. 26 shows an example SALD apparatus 2600 with thickness measurement devices 2602, 2604, in which multiple measurement devices of different types are used.

[0327] The apparatus includes a SALD head 2606 positioned with respect to a substrate 2608 that is conveyed along a conveyance path by a conveyance subsystem. The SALD head 2606 deposits first and / or second materials to form a barrier coating on the substrate 2608. Any suitable number of SALD heads 2606 may be used. First and second materials may be deposited in alternating layers.

[0328] A first measurement device 2602 is positioned downstream of the SALD head 2606 to measure a thickness of the first material, i.e., zinc oxide. The first measurement device 2602 is configured to obtain a strong signal from zinc oxide and a weaker signal or no signal from aluminum oxide. The first measurement device 2602 may include an X-ray fluorescence spectrometer, an ultraviolet (UV) light spectrometer, an ellipsometer, a reflectometer, or a visible light spectrometer. As such, the first measurement device 2602 measures a total thickness of zinc oxide in the barrier coating.

[0329] A second measurement device 2604 is positioned downstream of the first measurement device 2602 to measure a total thickness of the barrier coating. The second measurement device 2604 is configured to obtain a strong signal from both zinc oxide and aluminum oxide, or at least a strong signal from the coating as a whole. The second measurement device 2604 may be an X-ray fluorescence spectrometer, an ultraviolet (UV) light spectrometer, an ellipsometer, a reflectometer, or a visible light spectrometer. The thickness of the substrate 2608 may also be captured in the measurement. Since the thickness of the substrate 2608 is expected to be known, it can be subtracted from the measurement to obtain the thickness of the barrier coating. As such, the second measurement device 2604 measures a total thickness of the barrier coating.

[0330] The thickness of the second material, i.e., aluminum oxide, may be computed by subtracting the thickness of zinc oxide measured by the first measurement device 2602 from the total thickness of the barrier coating obtained with the second measurement device 2604. As mentioned above, the thickness of the substrate 2608, being an at least nominally known value, can be subtracted from the total thickness measured by the second measurement device 2604.

[0331] For the purpose of quality control, the zinc oxide, aluminum oxide, and / or total barrier coating may each have a minimum thickness requirement, according to one set of embodiments. Each may have a maximum thickness requirement, according to one set of embodiments. As such, the as-deposited thickness of any or all materials may be compared to a respective thickness requirement and used to determine whether the barrier coating should be accepted or rejected. The minimum and / or maximum thickness requirements may be manually or automatically determined, depending on the application.

[0332] If the thickness of the first material (zinc oxide), thickness of the second material (aluminum oxide), or the total thickness of the barrier coating fails to conform to a thickness requirement, an intervention may be made. Example interventions include changing a rate of deposition of the first material, changing a rate of deposition of the second material, and changing a speed of conveyance of the substrate. Such an intervention may bring the barrier coating or materials thereof closer to expected thickness.

[0333] It should be mentioned that, as the barrier coating is built up in layers of first and second material, a thickness measurement may be zeroed (tared) with respect to a previous thickness measurement, so that an individual layer’s thickness can be determined. For example, a thickness measurement may be taken after a zinc oxide layer is deposited (e.g., after each zinc oxide layer is deposited). Such measurement describes the running total thickness of zinc oxide in the barrier coating. At the same time, a previous layer’s measurement may be subtracted from a current layer’s measurement to compute the thickness of the current zinc oxide layer. The same applies to the total barrier coating thickness measurement. The thicknesses of layers that are not directly measurable, such as aluminum oxide, may be computed from this information.

[0334] Measurement devices of different types are used among a series of SALD heads, according to one set of embodiments. For example, when SALD heads are positioned at intervals along a conveyance path of a substrate, measurement devices may be placed at intervals between the SALD heads, in any of a variety of suitable arrangements. In some embodiments, the apparatus comprises a moveable measurement device. For example, a measurement device may have a position controllable by an actuator, such as linear actuator. The measurement device can therefore move with respect to the SALD heads, depending on the embodiment, allowing thickness measurements at variable intervals, depending on the embodiments, and allowing use of the same measurement device to characterize the performance of different SALD heads. This approach can reduce the cost / complexity of the apparatus, particularly if the measurement device is costly and / or complex. An actuator may be controlled to move a measurement device to capture measurements at different locations along a production line automatically and without human intervention.

[0335] The following examples are intended to illustrate certain embodiments of the present disclosure, but do not exemplify the full scope of the disclosure.

[0336] EXAMPLE 1

[0337] This example illustrates the performance of non-limiting barrier coatings prepared using SALD. The barrier coatings each comprised bilayers of AlOx with either zincone or ZnOy. Table 1 shows the composition of each barrier coating, identifying the number of bilayers, the composition of each layer of the bilayer, and the thickness of each layer. The barrier coatings were disposed on polymer substrates. In some cases, layers were laminated to the substrate, while in other cases, layers were not laminated and were free-standing on top of the substrate. Whether the layer was laminated is indicated in Table 1.

[0338] Table 1: Composition of nonlimiting barrier coatings

[0339] Table 2 shows each coating’s as-fabricated oxygen transmission (measured under simulated warehouse conditions) and / or water transmission (measured under simulated tropical conditions). As shown in the table, all the coatings had an oxygen transmission of less than or equal to 10 cc / m2-day and, has a water transmission of less than or equal to 25 g / m2-day, indicating that every coating performed well as a barrier coating, and generally demonstrating the advantages of the barrier coatings provided herein.

[0340] Table 2: Performance of nonlimiting barrier coatings Table 2 further demonstrates the barrier properties of at least some of the fibers after the barrier coatings were texted for flex durability using 300 cycles of Gelbo flex testing. As shown in the table, laminated samples 9-11 comprising the zincone showed extraordinarily good barrier properties even after flex durability testing, demonstrating the advantages of these barrier coatings for, e.g., consumer packaging applications. The analysis was supplemented with SEM imaging of Sample 1 (comprising an A1OX- Zincone bilayer), shown in FIG. 27 and Sample 4 (comprising an analogous AlOx-ZnOybilayer), shown in FIG. 28. As shown, both barrier coatings were damaged by the flex durability testing. However, Sample 1, as shown in FIG. 27, showed evidence of plastic deformation of the barrier coating, while Sample 4, as shown in FIG. 28, showed evidence of brittle fracturing. This difference illustrates that different deformation modes can be achieved using different barrier coatings generally provided herein, and indicates that, at least a result of its plastic deformation, barrier coatings comprising metalcones may be advantageous for use in tough barrier coating, since without wishing to be bound by any particular theory, it is believed that in at least some embodiments a plastically deformable barrier coating may be tougher than a barrier coating susceptible to brittle fracture. This deformation mode may relate to the extremely high barrier performance of the barrier coatings subjected to Gelbo flex testing.

[0341] Collectively, these results demonstrate the advantages and high performance of the barrier coatings provided herein.

[0342] EXAMPLE 2

[0343] This example illustrates use of an atmospheric -pressure spatial atomic layer deposition method to produce non-limiting layered articles by depositing Al Oa-ZnO nanolaminate coatings on compostable polylactic acid (PEA) and recyclable polyethylene terephthalate (PET) films. The articles were designed for sustainable packaging and the nanolaminate coatings, which comprised alternating layers of aluminum oxide (AI2O3) and zinc oxide (ZnO) with thicknesses in the nanometer range, was tested for barrier coating performance. The nanolaminates were observed to provide a superior gas- and vapor-diffusion barrier than a single-layer coating. Without wishing to be bound by any particular theory, the improvement was believed to stem from defect- decoupling effects and improved mechanical properties, as well as the ultrathin nature of the coatings, which simplified recycling and composting of the articles.

[0344] The nanolaminate coatings were deposited using an atmospheric-pressure spatial atomic layer deposition (AP-SALD) technique that was fast and scalable for the packaging industry. The depositions were carried out at 50°C to limit power consumption and preserve the integrity of the packaging material. For example, PLA begins to depolymerize at 75°C and decomposes at 290°C, while PET’s glass-transition temperature is around 70°C, so deposition at temperatures below these temperatures improved substrate integrity for these particular substrate materials. The AP-SALD technique allowed precise control over the nanolaminate architecture, so nanolaminate coatings with a range of layer thicknesses and various number of layers were studied to analyze the impact on barrier performance and flex resistance.

[0345] Scalable deposition of nanolaminate coatings on flexible packaging materials

[0346] Thin coatings of AI2O3 and ZnO were deposited onto flexible PLA and PET packaging films in open-air using a custom-built AP-SALD system. The AP-SALD system, as generally described herein. The AP-SALD system used a close-proximity reactor head, as shown in EIG. 29A, with a 30% V / V mixture of hydrogen peroxide in deionized water as the oxidant and gaseous diethylzinc (DEZ) and trimethylaluminum (TMA) as the metal precursors. Water- vapor and metal-precursor gas channels located on the underside of the reactor were spatially separated by nitrogen-curtain channels (green in EIG. 29 A) and exhaust channels (not shown in EIG. 29 A), which prevent the oxidant from intermixing with the flow of DEZ or TMA. In a reciprocating AP-SALD system, the packaging film was moved back and forth underneath the reactor head on a heated stage, sequentially exposing the film to the oxidant and metal-precursor gas streams. At first, a monolayer of the oxidant was adsorbed on the surface of the film, followed by exposure to the metal precursor (DEZ or TMA), which reacted to form an atomic layer of metal oxide. The second oxidant exposure completes the reaction, passivating unreacted ligands from the TMA and DEZ. The rapid (0.55 m / s), reciprocal motion of the packaging film built up a coating one atomic layer at a time, providing atomic-scale thickness and composition control. Nanolaminate structures were achieved using automated pneumatic valves that switched between DEZ and TMA flows. Deposition rates of 12 run AhOa / in and 11 nm ZnO / min were used herein, rates capable of being used at scale in the packaging industry.

[0347] FIGS. 29A-29C show metal-oxide nanolaminate barrier coatings. FIG. 29A shows an AP-SALD reactor head used for scalable deposition of metal-oxide layers. FIG. 29B shows a schematic of single-layer AI2O3 and ZnO coatings on a flexible PLA packaging film.

[0348] Flexible PLA and PET films (approximately 26 cm by 12 cm in size and 22.53 pm thick for PLA and 26 pm thick for PET) were fixed on a reciprocating heating stage, which was held at 50 °C to prevent damage to the films. Detailed parameters for the AP- SALD process are outlined in Table 3.

[0349] Table 3: Atmospheric -pressure spatial atomic layer deposition parameters

[0350] Several configurations of coatings were deposited, including single-layer AI2O3 and ZnO and nanolaminate (NL) coatings with 1, 2, 4, or 8 stacks, where a stack refers to one layer of AI2O3 plus one layer of ZnO.

[0351] The total thickness of the coatings was fixed at a nominal 96 nm (based on ellipsometry measurements); hence, the nominal thickness of the individual nanolaminate layers was 48 nm for the 1-stack, 24 nm for the 2-stack, 12 nm for the 4- stack, 6 nm for the 8-stack, and 3 nm for the 16-stack nanolaminate. Single-layer coatings were also deposited on silicon wafers and analyzed by X-ray photoelectron spectroscopy (XPS) to confirm they were AI2O3 and ZnO. The samples were sputtered with Ar for 30 sec prior to XPS measurement. The O / Al ratio for the AI2O3 was 1.67, while the O / Zn ratio for the ZnO was 1.35. These ratios were broadly consistent with stoichiometric AI2O3 and ZnO, but indicated an excess of oxygen in the films. The oxygen excess was believed to help improve the adhesion between the coating and the substrate.

[0352] The nucleation of AI2O3 and ZnO coatings on the PLA packaging film was studied. FIGS. 30A-30E show a characterization of nanolaminate coatings on PLA using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray Diffraction (XRD).

[0353] FIG. 30A shows a SEM image of the surface of a bare PLA film; it was non- uniform, containing pores that would act as pathways for water and oxygen molecules. Approximately 4 nm of AI2O3 or ZnO was deposited on the PLA. It was found that the AI2O3 provided more uniform coverage, coating all the pores, whereas significant porosity was still observed for the ZnO coating.

[0354] Due to the better initial coverage of the AI2O3, AI2O3 was chosen as the first (substrate-contacting) layer in all nanolaminate coatings. FIG. 30B shows the surface of an 8-stack nanolaminate; a smooth surface morphology was observed that covered all pores.

[0355] FIG. 30C shows a cross-sectional transmission electron microscopy (TEM) image of a 4-stack nanolaminate coating on PLA and FIG. 30D shows the corresponding energy-dispersive X-ray spectroscopy (EDX) mapping. The individual AI2O3 and ZnO layers were distinct and continuous. The TEM indicated an actual layer thickness of 9+1 nm, slightly thinner than the nominal value of 12 nm based on ellipsometry measurements.

[0356] When deposited at low temperatures (<100 °C), AI2O3 is known to be amorphous. ZnO, on the other hand, was expected to be polycrystalline. X-ray diffraction (XRD) analysis of the single-layer ZnO coating on PLA (middle trace in FIG. 30E) confirmed its polycrystallinity, with reflections from the (100), (101), (110), and (112) planes clearly visible. However, in the nanolaminate structure, the poly crystallinity of the ZnO layers was suppressed. The only peaks in the XRD pattern of the 8-stack nanolaminate (top trace in FIG. 30E) correspond to the underlying PLA film (bottom trace in FIG. 30E). This suppression is believed to have occurred due to the alternating deposition of amorphous AI2O3 layers, which disrupted the continuity of the ZnO, preventing crystallization. The suppression of grain formation achieved better barrier performance because grain boundaries in poly crystalline materials can act as pathways for gas and vapor diffusion. Since the glass transition temperature of PLA is 60°C, XRD analysis was also performed on bare PLA films after heating to 50°C, 60°C, and 70°C for 30 minutes to assess whether the AP-SALD process damaged the packaging film (FIG. 31). FIG. 31 shows XRD of bare PLA after heating at different temperatures for 30 minutes. No change was observed, indicating that the PLA remained stable.

[0357] Barrier performance of nanolaminate coatings

[0358] Having demonstrated the production of metal-oxide nanolaminate coatings on flexible PLA packaging films, the gas- and vapor-barrier performance of the coatings was then studied. The water vapor transmission rate (WVTR) of the coated PLA films was measured over 25 cycles, requiring approximately 18 hours, at 38 °C and 90% relative humidity (details in the Methods section).

[0359] FIGS. 32A-32C show WVTR measurements of as-deposited coatings on PLA. FIG. 32A shows the 1stand 25thWVTR measurements of all samples. FIG. 32B shows WVTRs (25 measurement cycles) for bare PLA, 96-nm ZnO on PLA and 96-nm AI2O3 on PLA. FIG. 32C shows WVTRs (25 measurement cycles) for nanolaminates with different numbers of stacks. FIG. 32A compares the 1stand 25thWVTR measurements for the bare PLA, single-layer AI2O3 and ZnO on PLA, and nanolaminate coatings on PLA. The WVTRs were lower for the nanolaminate coatings, demonstrating that they provided a better vapor barrier than the single-layer coatings. Moreover, as the number of layers increased, the barrier performance improved. It was noted that the WVTR of the single-layer coatings, particularly the ZnO, evolved over the 25 measurements cycles, whereas the WVTRs of the nanolaminate coatings remained relatively constant, suggesting the nanolaminates provided a more stable barrier than single-layer ZnO.

[0360] FIG. 32B shows the WVTRs for the bare PLA and single-layer coatings over the 25 measurement cycles. The WVTR of bare PLA increased slightly throughout the measurements, which was attributed to the fact that some polymers absorb water over time, causing them to swell and become more flexible (plasticization). This reduced the PLA’s resistance to vapor diffusion. AI2O3 is traditionally recognized as an excellent vapor barrier, with a WVTR as low as 10'5g- m’2-24hr_ |on rigid substrates. However, it was seen in FIG. 32B that the performance of AI2O3 was lower when deposited on flexible films like PLA, possibly because of the intrinsic hydrophilicity of PLA, coating imperfections, and / or differences in thermal expansion coefficients.

[0361] Of note, the WVTR of the single-layer AI2O3 coating improved slightly over time in FIG.32B, which may have resulted from defect saturation, whereby water permeation pathways become filled and causing structural relaxation or shrinkage that reduced vapor diffusion. ZnO demonstrated a lower WVTR than AI2O3 in the initial measurement cycles, which may have resulted from the fact that ZnO films were usually denser than AI2O3. However, the WVTR of the single-layer ZnO increased sharply over time. It was seen in FIG. 32B that by the final measurement cycles, the single-layer ZnO did not provide any vapor-barrier enhancement, as compared to the bare PLA. This was due to chemical degradation of the ZnO, which was known to be electrochemically unstable in aqueous environments.

[0362] Of greater interest were the WVTRs of the nanolaminate coatings over the 25 measurement cycles (FIG. 32C). The WVTR decreased as the number of stacks increased, as the increasing number of layers / interfaces better disrupt gas-permeation pathways. By adding an 8-stack or 16-stack nanolaminate that was only 96 nm thick (nominal), the WVTR of the 22.5 m-thick PLA was reduced from -300 g- m’2-24hr_ |to <0.5g-m'2-24hr-1, making it highly relevant for packaging applications. Many commercial food-packaging materials, for example, require WVTRs below 1 g-m'2-24hr"1to ensure product stability. This barrier performance of <0.5 g-m'2-24hr-1was achieved without sealing layers (lamination). Encouragingly, the WVTR of the nanolaminate coatings remained stable over the 25 measurement cycles (40 minutes each cycle including re-zero for 20 minutes and testing for 20 minutes) in FIG. 32C, indicating that the nanolaminate structure also prevented humidity-induced degradation of the ZnO layers.

[0363] The ZnO coating was found to become porous over time in the humid conditions. To study the instablity of ZnO-containing coatings, several of the coatings were stored at 38 °C and 90% RH for 5 days in an environmental chamber (FIGS. 33A-33D). FIG. 33A shows SEM of 96-nm ZnO on PLA after 5 days. The degradation of the ZnO and formation of a porous film structure was visible. FIG. 33B shows XRD of 96-nm ZnO on PLA and bare PLA after 5 days. Despite the visible degradation, XRD peaks corresponding to ZnO were still visible. The ZnO degradation may have corresponded to the formation of Zn(0H)2, a porous and hydrophilic byproduct of ZnO hydrolysis; however, the expected location of the (101) Zn(OH)2 peak coincides with a PLA peak. SEM of a 16-stack nanolaminate on PLA (FIG. 33C) and 8-stack nanolaminte on PLA (FIG. 33D) after 5 days. Degradation to a porous film structure was evident in the 16- stack nanolaminate, whereas the 8-stack nanolaminate better retains its original morphology.

[0364] To evaluate the flex resistance of the nanolaminate coatings, bending tests were performed on coated PLA films (26 cm x 4 cm) suspended from a 7 cm-diameter roller. A 1-kg weight was attached to the films to apply uniform tension during bending, similar to what would be experienced in a roll-to-roll process. The roller was rotated counterclockwise 360° and then returned to its starting position, completing 25 and 50 bending cycles. After bending, the WVTRs were measured to assess any changes in barrier performance.

[0365] FIGS. 34A-34G show bending studies on PLA. FIG. 34A shows a schematic of the bending setup. FIG. 34B shows WVTRs (25thmeasurement cycle) after 0, 25 and 50 bends. FIGS. 34C-34D show WVTRs (25 measurement cycles) for nanolaminates with different numbers of stacks after 25 bends (FIG. 34C) and 50 bends (FIG. 34D). And FIGS. 34E-34G show cross-sectional TEM images of (FIG. 34E) 4-stack, (FIG. 34F) 8- stack, and (FIG. 34G) 16-stack nanolaminates.

[0366] As shown in FIG. 34B bare PLA showed a small increase in WVTR from 288 g-m'2-24hr_1prior to bending to 340 g- m’2-24hr_ |and 358 g- m’2-24hr_ |after 25 and 50 bends, respectively. This was attributed to the alignment of polymer chains by the applied stress, which was apparent from changes in the surface morphology. After 50 bends, the single-layer AI2O3 and ZnO coatings and the 1 -stack nanolaminate had WVTRs similar to the bare PLA, indicating they provided little barrier to water vapor. In contrast, all nanolaminate coatings with 2 stacks or more retained WVTRs on the order of 10 g-m'2-24hr-1or less after 50 bends. The superior crack resistance of the nanolaminate coatings was attributed to the crack deflection effect, whereby cracks were redirected along interfaces between layers, dissipating energy and preventing direct propagation through the material. This conclusion was supported by SEM analysis in FIGS. 35A-35J.

[0367] FIGS. 35A-35J show SEM images of films before and after various bending tests. FIGS. 35A-35C show: 96-nm ZnO on PEA before bending (FIG. 35A), after 25 bends (FIG. 35B), and after 50 bends (FIG. 35C). FIGS. 35A-35C show: 96-nm AI2O3 on PEA before bending (FIG. 35D) and after 50 bends (FIG. 35E). FIGS. 35F-35J show 1 -stack (FIG. 35F), 2-stack (FIG. 35G), 4-stack (FIG. 35H), 8-stack (FIG. 351), and 16-stack (FIG. 35J) nanolaminates on PEA after 50 bends.

[0368] FIGS. 35A-35E show that prominent cracks were formed in the single-layer AI2O3 and ZnO coatings after 25 and 50 bends, consistent with brittle failure. FIGS. 35F- 35G show that some cracks were also formed in the 1-stack nanolaminate and 2-stack nanolaminate after 50 bends, suggesting the thickness and / or number of nanolaminate layers did not completely avoid cracking. In contrast, no cracks were observed in the 4- stack, 8-stack, or 16-stack nanolaminate coatings after 50 bends (FIGS. 35H-35J). The slight increase in the WVTR observed in those nanolaminate coatings after bending (FIG. 34B) may be due to gradual degradation of the coating in the humid testing conditions, microcracking, and / or delamination between the layers.

[0369] It was seen in FIG. 34B that before bending (0 bends) and after 25 bends, the vapor-barrier performance improves as the number of nanolaminate layers increases. However, after 50 bends, the 16-stack nanolaminate experienced a significant increase in WVTR. To understand this, the WVTR curves were examined in more detail in FIGS. 34C-34D. The 2-, 4-, and 8-stack nanolaminates that have been bent 25 times (FIG. 34C) and 50 times (FIG. 34D) remained relatively stable over the 25 measurement cycles, indicating a promising combination of vapor-barrier performance, bending resistance, and stability in the humid testing environment. On the other hand, the 16-stack nanolaminate that was bent 50 times showed a sharp increase in WVTR in the final measurement cycles (FIG. 34D), which was caused by chemical degradation of the coating. To understand why the 16-stack nanolaminate degraded over time after bending and the other nanolaminate coatings did not, cross-sectional TEM of the 4-, 8-, and 16- stack nanolaminates was performed. FIGS. 34E-34F show that the 4- and 8-stack coatings were composed of continuous AI2O3 and ZnO layers, whereas FIG. 34G reveals that as the individual layers approached a nominal thickness of ~3 nm in the 16-stack nanolaminate, they lost their continuity. As a result, the 16-stack nanolaminate coating was a mixture of the AI2O3 and ZnO components, rather than a true nanolaminate structure with isolated layers. Thus, when bending-induced microcracks created pathways for moisture into the coating, ZnO degradation could proceed throughout the bulk of the coating, similar to what was observed in the single-layer ZnO coating shown in FIG. 33A. Continuous AI2O3 layers were not present in the 16-stack nanolaminate to separate the ZnO layers and disrupt their degradation. This example illustrates that continuity of the individual layers of a multilayered structure can improve barrier coating performance.

[0370] Having established the excellent water-vapor-barrier properties and bending resistance of the metal-oxide nanolaminate coatings, the oxygen transmission rate (OTR) of the barrier coating was then characterized. The 8-stack nanolaminate coating was selected for study, as it has the best combination of low WVTR, high bending resistance, and chemical stability. OTRs were measured over 15 cycles using the same conditions as the WVTR measurements (38 °C and 90% relative humidity).

[0371] FIGS. 36A-36B show OTRs measured at 90% relative humidity and 38 °C before and after bending: bare PEA (FIG. 36A), 8-stack nanolaminate on PEA (FIG. 36B). As shown in these figures, the 8-stack nanolaminate substantially reduced the OTR relative to the OTR of bare PEA.

[0372] FIGS. 37A-37D show the effect of bending on the oxygen transmission of PEA (FIGS. 37A-37B) and on the water vapor transmission of PET (FIGS. 37C-37D) at 90 % RH and 38 °C before and after bending.

[0373] FIG. 37A shows that the OTR of the bare PEA was on the order of 1000 cm3-m'2-24hr_ |and increased with bending, which was explained by stress-induced alignment of PEA chains. FIG. 37B shows that adding the 8-stack nanolaminate on the PEA significantly reduced OTR to ~10 cm3- m’2-24hr_ |. Furthermore, the oxygen barrier was maintained after bending. OTR values were still ~10 cm^m’^ dhr’1after 25 bends and ~20 cm^m^’ dhr’1after 50 bends. These OTR values were within the range needed for many air-sensitive products, such as meat and dried snack foods. As noted before, these promising OTRs were achieved without the lamination of an additional PLA film on top of the coating.

[0374] To demonstrate the broad applicability of the nanolaminate coatings developed as described herein, a recyclable PET film was coated with the 8-stack metal-oxide nanolaminate and the WVTR was measured before and after bending. FIG. 37C shows that the WVTR of the bare PET was ~52 g- m’2-24hr_ |before and after bending. But as shown in FIG. 37D, when the PET was coated with the 8-stack nanolaminate, the WVTR dropped to a value below the measurement limit of the commercial WVTR tester (0.005 g-m'2-24hr-1), even after the coating was bent 50 times. The nanolaminate coating provided exceptional barrier performance on PET and the observed bending resistance was remarkable, given that the nanolaminate was composed of ceramic metal-oxide layers.

[0375] Gelbo flex testing and lamination

[0376] To further evaluate the applicability of the metal-oxide nanolaminate coatings for sustainable flex packaging, Gelbo flex tests were performed on the 8-stack nanolaminate on PET. Gelbo was an industry-standard testing method used to evaluate the flex durability of flexible barrier materials. During the test, a coated film was subjected to simultaneous twisting and crushing motions. Five different Gelbo tests were conducted based on the ASTM F392 standard for flexible packaging. They were outlined in Table 4, where test 1 was the gentlest and test 5 was the harshest.

[0377] Table 4: Gelbo test conditions FIGS. 38A-38D provide Gelbo flex-durability testing setup and results. FIG. 38A provides a schematic of the Gelbo experiment. FIG. 38B shows WVTRs (1stand 25thmeasurement cycles) of an 8-stack nanolaminate on PET after the Gelbo tests outlined in Table 4. In some cases a second layer was laminated on top of the 8-stack nanolaminate as detailed below. FIG. 38C provides a schematic of a lamination process, illustrating the lamination of the nanolaminate between two layers of PET. FIG. 38D shows WVTRs (1stand 25thmeasurement cycles) after Gelbo testing of an 8-stack NL coating laminated between PET films.

[0378] FIG. 38B shows that the WVTR of the bare PET increased slightly after Gelbo test 5 was performed, suggesting that test 5 may have damaged the PET in a way that facilitated higher water-vapor transmission through the bare film. When the 8-stack nanolaminate was subjected to the Gelbo tests, the WVTR increased due to flex-induced damage to the coating. However, even when subjected to the harshest test, test 5, the WVTR only increased to ~15 g- m’2-24hr_ |.

[0379] FIGS. 39A-39B provide SEM images of an 8-stack nanolaminate on PET after Gelbo tests 4-5, showing the damage done to the coating by tests. A number of cracks are present on the surfaces. Nonetheless, due to its nanolaminate structure, the coating was able to maintain reasonable barrier properties. Furthermore, the WVTR of the 8- stack nanolaminate after the various Gelbo tests was stable throughout the 25 measurement cycles. FIG. 40A shows WVTRs of an 8-stack nanolaminate coating on PET after the Gelbo tests outlined in Table 4. These Gelbo tests were done with the coating on the surface of the PET film, whereas in full packaging structures, the barrier coating will typically be sandwiched between two flexible films.

[0380] To test a more realistic packaging structure, the 8-stack nanolaminate coating was laminated between two PET films, as shown in FIG. 38C. One PET film was coated with the nanolaminate using the AP-SALD process and an adhesive was applied to the other PET film. The two PET films were then laminated together using a metal roller and heated. The full details of the lamination process are provided in the Methods section. FIG. 38D shows the WVTR performance (1stand 25thmeasurement cycles) of laminated bare PET before and after Gelbo test 5, as well as the laminated 8-stack nanolaminate after Gelbo tests 4 and 5. FIG. 40B expands upon these results, presenting, for all measurement cycles, WVTRs of laminated bare PET before and after Gelbo test 5 and an 8-stack nanolaminate coating laminated between two PET films after Gelbo tests 4 and 5. Lamination of the nanolaminate coating between two layers further improved its flex durability. The 8-stack nanolaminate sandwiched between PET films retained WVTRs <0.6 g-m2-24hr-1and <2 g-m2-24hr-1after the harshest Gelbo tests (4 and 5, respectively), whereas the WVTR of laminated bare PET after Gelbo test 4 was >24 g-m2-24hr’1.

[0381] In addition to meeting industry requirements for barrier performance and flex resistance, this laminated packaging structure was well-positioned to satisfy sustainability regulations. Assuming the thickness of an Al Oa-ZnO nanolaminate coating was 72 nm (based on the actual layer thickness measured in FIG. 30C) and was sandwiched between two 26-pm-thick PET films, the mass percentages of Zn and Al in the packaging structure were only 0.23% and 0.08%, respectively, due to the nanoscale nature of the barrier coating (see Calculation 1, below), because it is suitable for the production of new PET films from the recycled article, without significant deterioration in the properties of the recycled material. The limited mass of material added by the nanoscale coating limits any impact on the mechanical properties of the recycled PET.

[0382] For industrial composting on the other hand, a packaging structure with the nanolaminate coating between two 22.5-pm-thick PLA films would contain less than 0.29 wt% Zn and 0.10 wt% Al. Due to the ultrathin nature of the coating, it would not prevent disintegration of the PLA during composting.

[0383] Conclusion

[0384] This example demonstrates the scalable deposition of metal-oxide nanolaminate coatings on flexible PLA and PET films for compostable and recyclable packaging was demonstrated herein. The nanolaminate coatings had excellent water-vapor and oxygen barrier properties and their barrier performance improves with the number of nanolaminate layers due to suppression of grain formation in individual layers, disruption of vapor-permeation pathways, and a greater chemical stability. The nanolaminate coating structure also improves the bending resistance of the coatings via a crack-deflection effect; however, as the layers become too thin (<3 nm), the continuity of the nanolaminate layers was lost and along with it the enhanced chemical stability after significant bending. Hence, it was found that continuity of the individual layers maximizes the benefits of the nanolaminate barrier coatings. An 8-stack nanolaminate coating was found to have an excellent combination of low OTR and WVTR (on both PLA and PET), high bending resistance and flex durability, and chemical stability.

[0385] Methods

[0386] AP-SALD of vapor- and gas -barrier coatings

[0387] Trimethylaluminum (93-1360, Strem Chemicals Inc.) was used as the metal precursor for AI2O3, while diethylzinc (93-3030, Strem Chemicals Inc.) was used for ZnO. For the oxidant, a 30% V / V mixture of hydrogen peroxide (7722-84-1, Sigma- Aldrich) and deionized water was used. Depositions were performed on a custom-built AP-SALD system. Nitrogen gas (99.999% purity, Linde) was used as a carrier gas to deliver the reactants to the AP-SALD reactor head. The metal and oxidant channels were spatially separated by nitrogen curtains and each channel was separated by exhaust channels, which remove excess gases and reaction side products. The deposition parameters were provided in Table 3. PLA (BiAx, 22.53 pin thick) and PET (CelPlast, 26 pm thick) films were used as substrates. Si (100) (ID695, University Wafer) wafers were used as substrates for XPS characterization.

[0388] Lamination of barrier coating between PET films

[0389] Lamination was done using an RK K-Control coater K202. An adhesive mixture was prepared by dissolving a 6:1 mixture of SUNLAM SB ADH LX-545 (91538076, SunChemical) and SUNLAM SB HARD IP70 (91538110, SunChemical) in ethyl acetate (34858-4L, Sigma Aldrich) with a approximate ratio of 1:2. The adhesive mixture was drop coated onto a bare PET film (without the nanolaminate coating) and evenly spread with the coater using a threaded rod (US#6, 15 mm in diameter) and dried over a 60°C hot plate for 5 mins to prepare lamination PET stickers. The wet thickness of the adhesive was estimated to be 12 pm with a targeted solid content of 40%. The lamination PET stickers were then evenly pressed on top of nanolaminate-coated PET films and rolled with a 2 kg roller on top of a hot-plate at 60°C to complete the lamination process. Laminated films were then left under laboratory conditions for 48 hours before performing any Gelbo flex-durability testing and transmission-rate measurements. Bending testing

[0390] Bending tests were performed by attaching a coated film to a stainless-steel roller 7 cm in diameter. The films were 4 cm in width and 20 cm in length. A 1 kg weight was attached to the bottom of the film to provide uniform tension. The roller was manually rotated counterclockwise 360° and then returned to its starting position, completing 25 and 50 bending cycles.

[0391] Gelbo flex-durability testing

[0392] Gelbo wearing was done using a Labthink C681 Flex Durability Tester. The films were fixed to the bottom and top stainless- steel platens. The parameters of the Gelbo wearing trials were outlined in the Results section in Table 4. Tests 1, 4 and 5 correspond to Conditions E, D and C in the ASTM F392 standard, respectively, while tests 2 and 3 were adapted versions of test 1.

[0393] Characterization

[0394] The thickness of the coatings was measured using a FilmSense FS-1EX ellipsometer with 6 wavelengths in the range of 200-1800 nm. SEM characterization was done using a Zeiss Leol530 Ultra Plus. Samples were sputtered with gold (~2-3 nm) and images were taken with 5 kV of accelerating voltage. XPS was done using a Nexsa G2 Surface Analysis System (Thermo Scientific) and the X-ray source was monochromatic Al K-alpha. The instrument was calibrated with metal reference samples (Au, Cu, and Ag). TEM examination was done using a Thermo Fisher Scientific Talos 200X operated at 200 kV accelerating voltage. XRD was done using grazing incidence X-ray diffraction with a Panalytical MRD XRD system, using Cu Ka radiation. WVTRs were measured using a LabThink C390H with the following parameters: temperature: 38°C; re-zero duration: 20 min; cell purging time: 30 sec; test humidity: 90% relative humidity; zero purging interval: 1; test duration: 20 min; number of cycles: 25; specimen werea: 5 cm2. OTRs were measured using a LabThink C230H with the following parameters: temperature: 38°C; re-zero duration: 45 min; cell purging time: 30 sec; test humidity: 90% relative humidity; zero purging interval: 1; no compensation; test duration: 30 min; number of cycles: 15; specimen area: 5 cm2.

[0395] Calculation 1: Determination ofZn and Al weight percentages in packaging structures To calculate the wt% of Zn and Al in the laminated PET structure, the following approach was used.

[0396] The thickness of two PET films would be equal to 52 pm, while the density of PET is approximately 1.38 g-cnT3. The planar mass can then be found using the following equation:

[0397] Planar mass = Thickness ■ Density

[0398] Meaning the planar mass of PET would be 0.0072 g-cnT2.

[0399] The thickness of ZnO would be 36 nm in the NL coating described herein, while the density of ZnO is approximately 5.61 g-cnT3. This gives a ZnO planar mass of 0.00002 g-cnT2.

[0400] Similarly, the thickness of AI2O3 would be 36 nm and it has a density of approximately 3 g-cnT3, resulting in an AI2O3 planar mass of 0.000011 g-cm'2.

[0401] To find the weight percentage (wt%) of the ZnO in the laminated structure the following equation was used:

[0402] This results in a wt% of 0.28% for ZnO, while the wt% of AI2O would be 0.15% by using the same approach.

[0403] To calculate the wt% of Zn, the following was used:

[0404] The molar mass of Zn was 65.38 g / mol and the molar mass of O was 16 g / mol, which results in a wt% (Zn) equal to 0.23%. The wt% (Al) would be 0.08% by using the same approach, based on a molar mass of 26.98 g / mol for Al.

[0405] Using the same method, the wt% of the elements in the laminated PLA structure can be found. The total thickness of PLA in the laminated structure was 45 pm, and the density of PLA was approximately 1.24 g-cm'3. This gives a PLA planar mass of 0.0056 g-cm'2. By following the previous calculations, the wt% (Zn) would be 0.29% and the wt% (Al) would be 0.10% in the laminated PLA structure.

[0406] While several embodiments of the present disclosure have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and / or structures for performing the functions and / or obtaining the results and / or one or more of the advantages described herein, and each of such variations and / or modifications is deemed to be within the scope of the present disclosure. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and / or configurations will depend upon the specific application or applications for which the teachings of the present disclosure is / are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the disclosure described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the disclosure may be practiced otherwise than as specifically described and claimed. The present disclosure is directed to each individual feature, system, article, material, and / or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and / or methods, if such features, systems, articles, materials, and / or methods are not mutually inconsistent, is included within the scope of the present disclosure.

[0407] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0408] The phrase “and / or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and / or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc. As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0409] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0410] As used herein, “wt%” is an abbreviation of weight percentage. As used herein, “at%” is an abbreviation of atomic percentage.

[0411] Some embodiments may be embodied as a method, of which various examples have been described. The acts performed as part of the methods may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include different (e.g., more or less) acts than those that are described, and / or that may involve performing some acts simultaneously, even though the acts are shown as being performed sequentially in the embodiments specifically described above.

[0412] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[0413] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

CLAIMSWhat is claimed is:

1. A layered article, the layered article comprising: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, wherein the layered article is recyclable or compostable.

2. The layered article of claim 1, wherein the layered article is recyclable according to the Recyclass Standard3. The layered article of claim 1, wherein the layered article is compostable according to the ISO 16929 standard within a period of less than or equal to 3 months.

4. The layered article of claim 1, wherein the layered article meets the APR Standard criteria for recyclability.

5. The layered article of claim 1, wherein the layered article is recyclable according to the “‘Voluntary Standard’ for Repulpability & Recyclability of Paper-Based Products”.

6. A layered article, the layered article comprising: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, wherein the barrier coating has two or more of the following properties:(i) a ratio of A1OXto ZnOyof greater than or equal to 1:2 and less than or equal to 5:2;(ii) a ratio of A1OXto SiOzof greater than or equal to 1:2 and less than or equal to5:2;(iii) an oxygen transmission of less than or equal to 25 cc / m2-day and, has a water transmission of less than or equal to 10 g / m2-day, and is transparent;(iv) at least 30 layers of the first layer and at least 30 layers of the second layer;(v) wherein the substrate comprises pinholes having an average diameter greater than or equal to 25 nm, but the barrier coating is substantially pinhole free; and(vi) wherein the substrate has an RMS roughness of greater than or equal to 5 micrometers but the thickness of the barrier coating varies by less than 100% from an average value of the thickness of the barrier coating.

7. The layered article of claim 6, wherein the substrate comprises pinholes having an average diameter greater than or equal to 25 nm, but the barrier coating is substantially pinhole free, and wherein the thickness of the barrier coating is less than or equal to 30 nm.

8. The layered article of claim 6, wherein the substrate comprises pinholes having an average diameter greater than or equal to 25 nm, but the barrier coating is substantially pinhole free, and wherein the thickness of the barrier coating is less than or equal to 15 nm.

9. A layered article, the layered article comprising: a substrate layer, wherein the substrate layer comprises paper having an average pinhole size of less than or equal to 25 nm; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer.

10. The layered article of claim 9, wherein the paper is calendared paper.

11. A layered article, the layered article comprising: a substrate layer;a barrier coating adjacent the substrate layer; and a sealant layer adjacent the barrier coating, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, and wherein the sealant layer is configured to be fused to itself to form a seal.

12. A layered article, the layered article comprising: a substrate layer; a barrier coating adjacent the substrate layer; and a primer layer disposed between the barrier coating and the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, and wherein the substrate comprises pinholes having an average diameter greater than or equal to 25 nm, but the primer layer comprises pinholes having an average diameter of less than or equal to 25 nm.

13. A layered article as in any one of the preceding claims, wherein the layered article is incorporated into a container.

14. A layered article as in claim 13, wherein the container is a closed container.

15. A layered article as in any one of claims 13-14, wherein the layered article covers greater than or equal to 90% of the boundary of the container by area.

16. A layered article as in any one of claims 13-15, wherein the container is a bottle, bag, pouch, box, sleeve, or other article suitable for packaging of consumer products.

17. A method comprising making a container from the layered article of any one of the preceding claims.

18. The method of claim 17, wherein the method comprises folding the layered article into the shape of the container.

19. The method of any one of claims 17-18, wherein the method comprises sealing the sealant layer to itself.

20. A layered article as in any one of the preceding claims, wherein the sealant layer is an outer layer of the layered article.

21. A layered article as in any one of the preceding claims, wherein the substrate comprises pinholes having an average diameter greater than or equal to 25 nm, but the primer layer comprises pinholes having an average diameter of less than or equal to 25 nm.

22. A layered article as in any one of the preceding claims, wherein each of the first layer and the second layer has a thickness of between about 3 nanometers and 30 nanometers.

23. A layered article as in any one of the preceding claims, wherein the barrier coating is ultraviolet-light-blocking.

24. A layered article as in any one of the preceding claims, wherein the barrier coating comprises an initiation layer that is thicker than all other layers of the barrier coating.

25. A layered article as in any one of the preceding claims, wherein the layered article is recyclable, biodegradable, or compostable.

26. A layered article as in any one of the preceding claims, wherein the barrier coating is food contact safe.

27. A layered article as in any one of the preceding claims, wherein the barrier coating has a thickness of greater than or equal to 10 nm and less than or equal to 100 nm.

28. A layered article as in any one of the preceding claims, wherein the barrier coating is transparent.

29. A layered article as in any one of the preceding claims, wherein the first layer comprises an oxide selected from the group consisting of MgO, A1OXand SiOx.

30. A layered article as in any one of the preceding claims, wherein the second layer comprises ZnOy.

31. A layered article as in any one of the preceding claims, wherein the barrier coating has an oxygen transmission of less than 1 cc / m2-day.

32. A layered article as in any one of the preceding claims, wherein the barrier coating has a water transmission of less than 1 g / m2-day.

33. A layered article as in any one of the preceding claims, wherein the barrier coating comprises a metalcone.

34. A layered article as in any one of the preceding claims, wherein the barrier coating comprises alucone.

35. A layered article, the layered article comprising: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises a zincone.

36. A layered article, the layered article comprising: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer,wherein the first layer comprises ZnOx, A1OXand / or SiOxand the second layer comprises a metalcone.

37. A layered article, the layered article comprising: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating has a thickness of less than or equal to 100 nm and a water transmission of less than or equal to 10 g / m2-day.

38. A layered article, the layered article comprising: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating has a water transmission of less than or equal to 0.1 g / m2-day.

39. The layered article of claim 38, wherein the thickness is less than or equal to 30 nm.

40. The layered article of claim 39, wherein the thickness is less than or equal to 10 nm.

41. A method of making a layered article, the method comprising: depositing a barrier coating on a substrate using spatial atomic layer deposition (SALD), wherein depositing the barrier coating comprises oxidizing a zincone precursor on the substrate using an aliphatic polyol, an alkoxy-substituted ether, a dialdehyde, or a diketone.

42. The layered article or method of any one of claims 36-41, wherein the layered article is configured to maintain a water transmission of less than or equal to 10 g / m2-day after a 300 cycle Gelbo flex test.

43. The layered article or method of any one of claims 36 and 39-41, wherein the metalcone is a zincone or an alucone.

44. The method of any one of claims 41-43, wherein the aliphatic polyol is a glycol.

45. The method of claim 44, wherein the glycol is ethylene glycol46. The layered article or method of any one of claims 36-45, wherein the ratio of Al:Zn in the barrier coating is greater than or equal to 1:3 and less than or equal to 3:1.

47. The layered article or method of any one of claims 36-46, wherein the barrier coating is deposited by SALD.

48. The layered article or method of any one of claims 36-47, wherein the substrate comprises paper.

49. The method of any one of claims 41-48, wherein the zincone precursor comprises diethylzinc.

50. A layered article, the layered article comprising: a substrate layer; and a barrier coating adjacent the substrate layer, wherein the barrier coating comprises at least a first layer and a second layer, the first layer alternating with the second layer, wherein the barrier coating maintains (i) an oxygen transmission of less than or equal to 25 cc / m2-day or (ii) a water transmission of less than or equal to 25 g / m2-day and / or an oxygen transmission of less than or equal to 10 cm2 / m2-day after a 100 cycleGelbo flex test.

Images