Recyclable heat-shrinkable film for recyclable containers
A recyclable shrink label with a light-blocking layer addresses the need for light-protective packaging by ensuring effective light protection and recyclability through separable label components during PET recycling.
Patent Information
- Application Number
- JP2025201062
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2021-05-14
- Filing Date
- 2025-11-20
- Publication Date
- 2026-02-24
AI Technical Summary
The market lacks recyclable, light-protective packaging options for products that require protection from harmful light waves, particularly in the food and dietary supplement industries, as color-impregnated PET bottles and containers are not effectively recycled.
A recyclable shrink label with a heat-shrink film and a light-blocking layer that blocks at least 80% of light between 200 nm to 900 nm, composed of materials like PET, PETG, PVC, OPS, PLA, PP, or PE, and includes a high opacity layer with pigments like TiO2, PCC, or alumina, allowing the label to be washed away during recycling.
The solution provides effective light protection for packaged contents while ensuring the recyclability of PET containers, as the label components separate from the PET during the recycling process, maintaining the integrity of the PET material for reuse.
Smart Images

Figure 2026031581000001_ABST
Abstract
Description
[Technical Field]
[0001] (Related Applications) This application claims priority to U.S. Provisional Patent Application No. 63 / 188,794, filed May 14, 2021, which is incorporated herein in its entirety. [Background technology]
[0002] The consumer packaged goods market globally desires to utilize recyclable packaging for most products. Clear PET packaging offers a cost-effective, recyclable option. Dairy, food, nutritional supplement, and other markets also require light-protective packaging to prevent harmful light waves from ingredients from affecting the shelf life and performance of these products. Traditionally, color-impregnated bottles or containers and / or white shrink film printed with, or sometimes without, a functional light-blocking layer are used to block harmful light waves. The market for recycling color-impregnated PET is very small, and most of these bottles and containers are not recycled.
[0003] Therefore, there remains a need for recyclable, light-protective packaging options for many markets, including the food and dietary supplement markets.
[0004] Any discussion of prior publication or other prior knowledge is not an admission that such material is published, publicly known, or part of the common general knowledge. Summary of the Invention
[0005] Disclosed herein are recyclable shrink labels.
[0006] According to one embodiment, a recyclable shrink label includes a heat shrink film having a first surface and a second surface opposite the first surface, and a light-blocking layer disposed adjacent to the first surface, the light-blocking layer including a light-blocking component, wherein the recyclable shrink label is configured to block at least 80% of incident light having a wavelength in the range of 200 nm to 900 nm. The heat shrink film may have a thickness of 15 μm to 100 μm or 30 μm to 80 μm.
[0007] The recyclable shrink label may further include an indicia layer. The indicia layer may be disposed on the first surface. The recyclable shrink label may further include a high opacity layer. The high opacity layer may include a white pigment. The high opacity layer may be disposed between the indicia layer and the light-blocking layer.
[0008] The heat shrink film may include or be made of polyester, polyolefin, or a combination thereof. In some cases, the heat shrink film includes or is made of polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG or PET-G), polyvinyl chloride (PVC), polystyrene or oriented polystyrene (OPS), polylactic acid (PLA), polypropylene (PP), polyethylene (PE), or a combination thereof. In some cases, the heat shrink film is made of polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG or PET-G), polyvinyl chloride (PVC), polystyrene or oriented polystyrene (OPS), polylactic acid (PLA), polypropylene (PP), polyethylene (PE), or a combination thereof. In some cases, the heat shrink film is made of polyethylene terephthalate (PET).
[0009] When heated to 100°C, the heat shrink film can shrink or contract by about 1% to about 90%. The heat shrink film can shrink or contract by about 1% to 90% in the horizontal direction. When heated to 100°C, the entire recyclable shrink label can shrink or contract by about 1% to about 90%. The entire recyclable shrink label can shrink or contract by about 1% to 90% in the horizontal direction.
[0010] The high opacity layer may comprise a pigment selected from titanium dioxide (TiO2), precipitated calcium carbonate (PCC), aluminum silicate, aluminum oxide (alumina), a mica-based pigment coated with a thin layer of white pigment, or combinations thereof.
[0011] The light-blocking component may include metal particles. The metal particles may have a particle size of 0.1 μm to 100 μm. The light-blocking component may include or consist of zinc, aluminum, copper, silver, or alloys thereof, titanium dioxide, carbon black, mica, reflective pigments, polymers capable of blocking light, minerals capable of blocking light, or combinations thereof. The light-blocking layer may be present on the label in an amount of 0.5 ppr to 25 ppr. The light-blocking component may be present in an amount of 0.1 ppr to 10 ppr, 0.2 ppr to 5 ppr, or 0.3 ppr to 3 ppr.
[0012] According to one embodiment, an article comprises a container including an exterior surface and the above-described recyclable shrink label disposed on the container. In some embodiments, a first surface of the heat shrink film faces the exterior surface of the container. The container may comprise or be made of a polymer, glass, metal, or a combination thereof. The container may comprise or be made of (e.g., consist of) polyethylene terephthalate (PET). The container may comprise or be made of (e.g., consist of) transparent polyethylene terephthalate (PET). The recyclable shrink label may comprise or be made of polyethylene terephthalate (PET). In some cases, polyethylene terephthalate (PET) forms the outermost layer of the recyclable shrink label.
[0013] According to one embodiment, a method of making a label for a container includes depositing an indicia layer on a heat-shrinkable film, optionally depositing a high-opacity layer on the indicia layer, and depositing a light-blocking composition on the indicia layer, the heat-shrinkable film, or the high-opacity layer, wherein the light-blocking layer comprises one or more light-blocking components, and wherein the label is capable of blocking at least 80% of incident light having a wavelength in the range of 200 nm to 900 nm.
[0014] According to one embodiment, a method for recycling an article includes a container defining an exterior surface and the above-described recyclable shrink label disposed on the container, optionally with a first surface facing the exterior surface of the container. The method includes determining that the container and the recyclable shrink label comprise polyethylene terephthalate (PET); directing the article to a polyethylene terephthalate (PET) recycling stream; and washing the article to remove ink and pigment from the recyclable shrink label. The washed article may be transparent and free of light-blocking components or other pigments or inks. The article may be washed in a caustic bath. The article may be cut into small pieces before washing. According to one embodiment, during the recycling process, the ink and coating layer cleanly separate from the PET heat shrink film, allowing pure PET to be recovered and processed into reusable resin.
[0015] The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies exemplary embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list.
[0016] definition The words "preferred" and "preferably" refer to embodiments of the invention that may offer certain benefits, under particular circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, or is intended to exclude other embodiments from the scope of the invention.
[0017] The terms "comprises" and variations thereof do not have a limiting meaning where these terms appear in the description and claims. Such terms are understood to mean the inclusion of the stated step or element or group of steps or elements but not to the exclusion of any other step or element or group of steps or elements.
[0018] "Consisting of" means including and limited to what follows the phrase "consisting of." Thus, the phrase "consisting of" indicates that the listed elements are required or essential, and that no other elements may be present. "Consisting essentially of" means including any elements listed after the phrase, and is limited to other elements that do not interfere with or contribute to the activity or action specified in this disclosure for the listed elements. Thus, the phrase "consisting essentially of" indicates that the listed elements are required or essential, but that other elements are optional and may or may not be present depending on whether they materially affect the activity or action of the listed elements.
[0019] As used herein, the term "substantially" has the same meaning as "nearly completely" and can be understood to modify the term that follows by at least about 90%, at least about 95%, or at least about 98%. As used herein, the term "not substantially" has the same meaning as "not significantly" and can be understood to have the opposite meaning of "substantially," i.e., modify the term that follows by 10% or less, 5% or less, or 2% or less.
[0020] Unless otherwise specified, "a," "an," "the," and "at least one" are used interchangeably and mean one or more than one.
[0021] As used herein, the term "or" is generally used in its ordinary sense, including "and / or," unless the context clearly dictates otherwise.
[0022] The term "and / or" means one or all of the listed elements or a combination of any two or more of the listed elements.
[0023] All references to standard methods (e.g., ASTM, TAPPI, AATCC, etc.) refer to the latest available version of the method at the time of filing of this disclosure, unless otherwise indicated.
[0024] Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).
[0025] As used herein, a reference to a number "up to" (eg, up to 50) is inclusive of that number (eg, 50).
[0026] The terms "in the range" or "within a range" (and similar descriptions) include the endpoints of the stated range.
[0027] For any method disclosed herein that includes separate steps, the steps may be performed in any feasible order, and any combination of two or more steps may be performed simultaneously, if desired.
[0028] All headings are for the convenience of the reader and should not be used to limit the meaning of the text that follows the heading, unless so specified.
[0029] Throughout this specification, references to "one embodiment," "an embodiment," "certain embodiments," or "some embodiments" mean that a particular feature, structure, composition, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of such phrases in various places throughout this specification are not necessarily all referring to the same embodiment of the present disclosure. Furthermore, the particular features, structures, compositions, or characteristics may be combined in any suitable manner in one or more embodiments.
[0030] Unless otherwise indicated, all numbers expressing quantities of ingredients, molecular weights, and the like used in the specification and claims should be understood as being modified in all instances by the term "about." When used herein in connection with a measured quantity, the term "about" refers to a variation in the measured quantity that would be expected by one of ordinary skill in the art making the measurement and exercising a level of care commensurate with the purpose of the measurement and the precision of the measuring device being used. Accordingly, unless otherwise indicated, the numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the doctrine of equivalents to the scope of the claims, each numerical parameter should, at the very least, be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
[0031] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible, however, all numerical values inherently contain ranges necessarily resulting from the standard deviations found in their respective testing measurements.
[0032] The terms "polymer" and "polymeric material" include, but are not limited to, organic homopolymers, copolymers, such as block, graft, and random copolymers, terpolymers, and the like, as well as blends and modifications thereof. Furthermore, unless otherwise specified, the term "polymer" is intended to include all possible geometric configurations of the material. These configurations include, but are not limited to, isotactic, syndiotactic, and atactic symmetries.
[0033] The term "copolymer" refers to a polymer containing two or more different monomer units or segments, including terpolymers, tetrapolymers, and the like.
[0034] As used herein, the term "ink" refers to coloring materials for writing and printing. Generally, inks have four main components: (1) a colorant composed of a pigment, dye, or a mixture of pigments and / or dyes that defines the color of the colorant; (2) a binder, which may be soluble or in a solvent, that holds the colorant on the substrate; (3) optionally, a solvent or water to dissolve the resin (the solvent or water is removed after printing on the label); and (4) optionally, additives to adjust the properties of the ink. Pigments can be organic or inorganic. Inks herein can be distinguished as metallic inks and non-metallic inks. As used herein, the term "metallic ink" refers to inks in which metal flakes or powders are added as pigment additives. Metallic inks can appear reflective or shiny when printed. Therefore, "non-metallic ink" herein refers to inks that do not contain such metal flake or powder components.
[0035] As used herein, the term "opaque" refers to a substrate or printed substrate that has an opacity of 50% or greater.
[0036] As used herein, the term "opacity" refers to a property of a substrate or print substrate that measures the substrate's ability to hide or obscure objects placed behind the substrate relative to a point of observation. Opacity can be reported as the ratio (in percent) of the diffuse reflectance of a substrate backed with a black body having 0.5% reflectance to the diffuse reflectance of the same substrate backed with a white body having 89% absolute reflectance. Opacity can be measured as described in ASTM D 589-97, Standard Test Method for Opacity of Paper (15° / Diffuse Illuminant A, 89% Reflectance Backing and Paper Backing). A highly opaque substrate does not allow much, if any, light to pass through the substrate. A low-opacity substrate allows much, if not all, light to pass through the substrate. Opacity can range from 0 to 100%. As used herein, the term "low opacity" refers to a substrate or print substrate having an opacity of less than 50%. As used herein, the term "high opacity" refers to a substrate or print substrate that has an opacity of 50% or greater.
[0037] As used herein, the term "indicia" refers to markings or displays that can be used to convey a message. The message conveyed can be an indication of source, characteristics of the product in the package, the quantity of product in the package, the quality of the product in the package, or any other message. An indicia can be a symbol, such as a graphic resembling a target used in marksmanship training to indicate a particular retail store. An indicia can be text in any language or combination of languages representing verbal communication. An indicia can be a pattern of color, lines, or a combination thereof. An indicia can be an illustration of a tangible object, such as an apple, to indicate the source of a particular brand of computer. An indicia can be artwork depicting a tangible object or a fanciful composition or marking of any type. A single dot of a single color can be an indicia. An indicia can be the type, texture, smell, or sound of movement of the material used to form the package. An indicia can also be a combination of any and all of the foregoing indicia.
[0038] As used herein, the term "ppr" refers to pounds per ream and is used as a unit of measure of dry pounds of ink or coating per area of substrate (e.g., film or label). One ream is 3000 square feet (approximately 289 m 2 ) is understood to mean
[0039] As used herein, the term "BCM" stands for billion cubic microns per square inch (μm 3 / inch 2 ) and is used as a unit of measurement for the liquid volume of an ink or coating.
[0040] As used herein, the term "line-screen" refers to the number of halftone lines printed per linear inch.
[0041] As used herein, the term "viscosity" refers to the flow rate of a liquid and is measured using a calibrated No. 2 Zahn viscosity cup.
[0042] As used herein, the term "COF" refers to the dynamic and static coefficient of friction values. COF can be measured as described in ASTM D1894-14 Standard Test Method for Static and Kinetic Coefficients of Friction of Plastic Film and Sheeting.
[0043] The present disclosure is further explained with reference to the drawings. These figures are idealized, not to scale, and are intended to be merely illustrative and non-limiting. [Brief explanation of the drawings]
[0044] [Figure 1A] 1A and 1B illustrate a schematic representation of one embodiment of the disclosed article, according to one embodiment. [Figure 1B] 1A and 1B illustrate a schematic representation of one embodiment of the disclosed article, according to one embodiment. [Figure 1C] 1A and 1B illustrate a schematic representation of one embodiment of the disclosed article, according to one embodiment. [Figure 1D] 1A and 1B illustrate a schematic representation of one embodiment of the disclosed article, according to one embodiment. [Figure 1E] 1A and 1B illustrate a schematic representation of one embodiment of the disclosed article, according to one embodiment. [Figure 2] 1 is a schematic diagram of an article comprising a label of the present disclosure, according to one embodiment. [Figure 3] 1 is a graphical representation of data from Example 1. [Figure 4] 1 is a graphical representation of data from Example 1. [Figure 5] 1 is a graphical representation of data from Example 1. DETAILED DESCRIPTION OF THE INVENTION
[0045] The present disclosure relates to opaque, recyclable labels. The present disclosure further relates to opaque, recyclable shrink labels.
[0046] The term label is used broadly herein. While many embodiments described herein may be characterized as shrink sleeves, the disclosure and the term label are not limited to such embodiments. A label may cover at least some clear or transparent portions of a package. A label can serve to block light from reaching the product within the package. A label may be used to provide graphical elements and information about the product, such as product information required by law (e.g., ingredient list and / or nutritional facts), if applicable.
[0047] According to one embodiment, the label of the present disclosure has a layered structure. The layered structure may include one or more shrink film layers and one or more light-blocking (opaque) layers. The layered structure may further include other layers, such as an additional polymer layer, indicia, adhesive layer, slip coat, protective top layer, another functional layer, or a combination thereof. Such additional layers may be disposed between the shrink film, indicia layer, high-opacity layer, or light-blocking layer, or on the outside of any such layer. The shrink film has a first surface and a second surface opposite the first surface. When the label is applied to a container (e.g., a bottle), the first surface may be the side facing the container, and the second surface may face the outside of the container. The light-blocking layer may be disposed adjacent to the first surface. That is, generally, the light-blocking layer may be disposed between the shrink film and the container. Other layers, if included, may be disposed adjacent to the first surface or the second surface. The term "adjacent" is used herein to indicate which side of the label a layer is closest to. Additional optional layers may be disposed between adjacent layers. The term "immediately adjacent" is used to indicate that the layers in question are in contact with each other, with no intervening layers.
[0048] It is desirable that the label be light-blocking (e.g., ambient light and sunlight, e.g., 200 nm to 900 nm) so that the contents of the container covered by the label can be protected from light. It is further desirable that the label be recyclable. Generally, a clear, crystalline heat-shrinkable film (e.g., PET shrink film) is considered recyclable if the ink on the film is not retained after the caustic wash cycle typically used in the PET recycling process.
[0049] Previously, white PET film with a black coating printed on the inside of the label was the only shrink label solution that met the desired light-blocking threshold. White PET cannot be recycled with clear PET bottles or containers, and therefore these products are not recycled and end up in landfills. According to one embodiment, the labels of the present disclosure are light-blocking, offering the ability to maintain and improve product shelf life with a light-blocking transparent shrink film while preserving the recyclability of clear PET packaging.
[0050] According to one embodiment, the inks utilized in the labels of the present disclosure, including light-blocking inks, are designed to wash away the film during the recycling process, allowing the label and the container it covers to be recycled.
[0051] Furthermore, according to one embodiment, the label of the present disclosure allows for the use of clear PET underneath a container or bottle, thereby preserving the recyclability of the container or bottle. The label can also potentially reduce or eliminate the need for any additional additives (e.g., pigments) in the container itself. For example, the label may be used on clear rigid PET containers and bottles. Any inks and coatings printed on the PET shrink film may be formulated to wash away the film during the recycling process, allowing the underlying clear PET film and clear PET rigid plastic to be recycled together. The inks and coatings may be formulated to come together in a coagulation-like reaction during the wash-off process, thereby preventing or reducing the ink and coating from staining the clear film and rigid PET present at the bottom of the PET caustic recycling bath process. For example, the inks and coatings may be crosslinked and / or have additives that help smaller particles aggregate into larger particles during the wash-off process. These larger particles can then be filtered from the wash water, helping to prevent staining of the PET film and clear PET rigid plastic.
[0052] film According to one embodiment, the label comprises a heat-shrinkable film or heat-shrink film. The terms heat-shrink film and shrink film are used interchangeably herein. Any suitable heat-shrink film may be used. In some embodiments, the heat-shrink film is a polyester heat-shrink film of the type used in the packaging industry. Heat-shrink film can also be described as a film that is not heat-stabilized so that it shrinks when exposed to heat.
[0053] A heat shrink film is a substantially two-dimensional polymer film having two major surfaces. The term substantially two-dimensional is used to refer to an object having a significantly larger size measurement in two dimensions compared to a significantly smaller size measurement in a third dimension (e.g., thickness). In some embodiments, useful heat shrink films or articles comprising such heat shrink films shrink 1% to 90% in the transverse direction (TD) and up to 10% in the machine direction (MD). In some embodiments, useful heat shrink films or articles comprising such heat shrink films shrink 1% to 90% in the machine direction and up to 10% in the transverse direction. As used herein, transverse direction means the direction perpendicular to the working direction. As used herein, machine direction means the direction parallel to the working direction.
[0054] The composition of the heat shrink film, whether two-dimensional or three-dimensional, is not particularly limited and may include high density polymers or low density polymers, or combinations thereof. 3 Low density polymers having a density of less than 1 g / cm may be preferred. Such low density allows for water flotation separation from denser substrates during the recycling process. In some embodiments, the label has a density of less than 1 g / cm. 3 A heat shrink film having the following density is provided:
[0055] According to one embodiment, the label comprises a heat shrinkable film having a thickness of 15 μm or more, 30 μm or more, 35 μm or more, 37 μm or more, 40 μm or more, 45 μm or more, 50 μm or more, or even 60 μm or more. Preferred heat shrinkable films are comprised of films having a thickness of 100 μm or less, 90 μm or less, 90 μm or less, 85 μm or less, 80 μm or less, 75 μm or less, 70 μm or less, 65 μm or less, or even 60 μm or less. In some embodiments, the heat shrinkable film has a thickness in the range of 15 μm to 100 μm, 30 μm to 80 μm, 40 μm to 60 μm, or even 40 μm to 55 μm.
[0056] According to one embodiment, the label comprises a heat-shrinkable film that shrinks when heated above a shrinkage initiation temperature. The shrinkage initiation temperature may be greater than 22.5°C or within a range of about 40°C to about 200°C. The shrinkage of a heat-shrinkable film is typically measured using a hot water bath method, in which the film is immersed in a heated water bath for 10 seconds. The measurement may be repeated at different temperatures, such as 100°C and 80°C. The shrinkage may be reported at a given temperature or presented as a shrinkage curve, where the shrinkage number is measured at 100°C. When heated to 100°C, the heat-shrinkable film shrinks by 1% or more, 2% or more, 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more of its pre-heated size. When heated to 100°C, the heat-shrinkable film shrinks by 90% or less, 80% or less, 75% or less, 70% or less, or 50% or less of its pre-heated size. When heated to 100°C, the heat shrinkable film may shrink 1% to 90%, 2% to 80%, or 5% to 70%. The shrinkage may be in the machine direction, the cross direction, or both. In some embodiments, the heat shrinkable film shrinks primarily in the cross direction only. In some embodiments, the heat shrinkable film shrinks primarily in the machine direction only.
[0057] In some embodiments, polymeric films useful for labels have balanced shrinkage characteristics. Balanced shrinkage allows the film to tighten darts and wrinkles that initially form in the label when the label is applied to a curved surface, eliminating the darts and wrinkles with minimal distortion of the label's shape. In some embodiments, films used for labels have asymmetric shrinkage characteristics. Films with asymmetric shrinkage, i.e., films with high shrinkage in one direction and low to moderate shrinkage in other directions, can be particularly useful. In some embodiments, particularly useful films are those with unidimensional shrinkage (e.g., transverse) because they can provide the ability to more easily pre-distort indicia formed thereon relative to those with biaxial shrinkage. In some embodiments, films may be used in a process called "roll-on shrink-on," in which the film shrinks primarily in the longitudinal direction.
[0058] Preferably, the shrink film is heat shrinkable and also has sufficient stiffness (e.g., modulus) to be dispensed using conventional label application equipment and converting processes, including treating, printing, coating, slitting, seaming, cutting, and label application. The desired stiffness of the film depends on the size of the label, the application speed, the surface shape and moisture content of the container, and the label application equipment used.
[0059] Shrink films can be made by conventional processes, for example, shrink films can be manufactured using blown, calendered, or tenter extrusion processes.
[0060] Shrink films useful for labels may be monolayer or multilayer. One or more layers of the shrink film may be formed from a polymer selected from numerous types of polymers, including, for example, polyesters and polyolefins. Exemplary specific polymers or polymer types that can be utilized to form the shrink film include, for example, polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG or PET-G), polyvinyl chloride (PVC), polystyrene or oriented polystyrene (OPS), polylactic acid (PLA), copolymers, non-petroleum-based biopolymers, and copolymers and blends thereof. Additional exemplary specific types of polymers that can be utilized to form the shrink film include polyolefins such as polypropylene (PP), polyethylene (PE), and copolymers and blends thereof. In some embodiments, exemplary specific copolymers include, for example, copolymers of PP and PE. In a preferred embodiment, the shrink film comprises polyethylene terephthalate (PET) and is recyclable along with PET bottles. In some embodiments, the shrink film is comprised of polyethylene terephthalate (PET).
[0061] Shrink films are typically polymeric films applied over or around a substrate, such as a container (e.g., a bottle, jar, tube, etc.) or multiple containers (e.g., a multipack of containers). Two portions of the film (e.g., two edges) can be joined together to form a seal or seam resulting in a sleeve or tube configuration. When heated to 100°C, the shrink film can shrink or contract by 1% or more, 2% or more, 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more. When heated to 100°C, the shrink film can shrink or contract by 90% or less, 80% or less, 75% or less, 70% or less, or 50% or less of its size before heating. When heated above the shrink onset temperature, the shrink film can shrink or contract by 1% to 90%, 2% to 80%, or 5% to 70%. Shrinkage can be in the longitudinal direction, the transverse direction, or both. In some embodiments, the heat shrink film shrinks primarily in the transverse direction. In some embodiments, the heat shrink film shrinks primarily in the longitudinal direction only. The amount the shrink film shrinks can be largely dependent on, or can be selected based on, the container being shrunk. The film shrinks to conform to the contours of the underlying article. In one embodiment, the shrink film is microperforated to allow trapped air to escape from the interface between the label and the article to which it is adhered. In another embodiment, the shrink film is permeable to allow fluid to escape from the adhesive or from the surface of the article. In one embodiment, vents or slits are provided in the shrink film. In some embodiments, perforations, pinholes, or similar features may be desirably avoided to maximize light-blocking properties.
[0062] The layer of the shrink film or a layer applied to the shrink film may optionally contain pigments, fillers, stabilizers, light protectants, or other suitable modifiers, as desired.
[0063] The shrink film may have any suitable color. However, for recyclability, useful shrink films specifically include transparent shrink films and white shrink films (e.g., white floating films). Transparent shrink films can be made white by including one or more additional layers containing a pigment that causes the heat shrink film to appear white when viewed. White shrink films may also be made, for example, by adding a white pigment during the extrusion or molding process.
[0064] Useful shrink films may also include a layer of an ink-receptive composition that improves the printability of the shrink film and the quality of the resulting print layer. Various such compositions are known in the art and generally include a binder and a pigment, such as silica or talc, dispersed in the binder. The presence of the ink-receptive composition can reduce the drying time of some inks. Such ink-receptive compositions are described in U.S. Pat. No. 6,153,288 (Shih et al.), the disclosure of which is incorporated herein by reference.
[0065] Adhesion of the ink to the surface of the polymeric shrink film can be improved, if necessary or desired, by techniques known to those skilled in the art. For example, as described above, an ink primer or other ink adhesion promoter can be applied to the surface layer of the shrink film prior to application of the ink. Alternatively, the surface of the shrink film can be treated, for example, by methods such as corona treatment or flame treatment, to improve adhesion of the ink to the polymeric film layer.
[0066] Useful ink primers may be transparent or opaque, and the primers may be solvent-based, water-based, or UV-based digital printing inks diluted with known solvents and / or additives to achieve the desired viscosity for a particular printing process. In one embodiment, the primer is radiation-curable (e.g., UV). The ink primer may include a lacquer and a diluent. The lacquer may be composed of one or more polyolefins, polyamides, polyesters, polyester copolymers, polyurethanes, polysulfones, polyvinylidene chloride, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, ionomers based on sodium or zinc salts or ethylene methacrylic acid, polymethyl methacrylate, acrylic polymers and copolymers, polycarbonates, polyacrylonitriles, ethylene-vinyl acetate copolymers, and mixtures of two or more thereof. Examples of diluents that may be used include alcohols such as ethanol, isopropanol, and butanol; esters such as ethyl acetate, propyl acetate, and butyl acetate; aromatic hydrocarbons, e.g., ketones such as acetone and methyl ethyl ketone; aliphatic hydrocarbons such as heptane; and mixtures thereof. The lacquer to diluent ratio depends on the viscosity desired for application of the ink primer, and the selection of such a viscosity is within the skill of the art. The ink primer layer may have a thickness of from about 0.5 μm to about 20 μm, from about 1 μm to about 4 μm, or from about 1.5 μm to about 3 μm.
[0067] A transparent or non-transparent polymeric topcoat or overcoat layer may be present in the label of the present disclosure. The topcoat or overcoat layer can provide desirable protective properties to the label before or after the label is applied to an article such as a container. The presence of a transparent or non-transparent topcoat layer on the print layer can, in some embodiments, provide additional properties such as antistatic properties, rigidity, and / or weatherability. The topcoat can protect the print layer from, for example, weather, sun, abrasion, moisture, water, etc. The transparent or non-transparent topcoat layer can enhance the properties of the underlying print layer to provide a glossier, richer image. The transparent or non-transparent topcoat layer can change the aesthetics (e.g., matte finish or soft-touch finish) of the underlying print layer or label. The protective transparent protective layer can also be designed to be abrasion-resistant, radiation-resistant (e.g., UV-resistant), chemical-resistant, and heat-resistant, thereby protecting the label, particularly the print layer, from degradation due to such causes. The overcoat may also contain an antistatic or anti-blocking agent to provide easier handling when the label is applied to a container at high speed. The layer may be applied to the print layer by techniques known to those skilled in the art. The polymer film may be deposited from solution, or applied as a preformed film (laminated to the print layer), or by any other suitable means known in the art.
[0068] When a permeable or non-permeable topcoat or overcoat layer is present, it can have a single layer or a multi-layer structure. The thickness of the protective layer generally ranges from about 1 μm to about 125 μm, from about 12.5 μm to about 125 μm, and in one embodiment, from about 25 μm to about 75 μm. Examples of topcoat layers are described in U.S. Pat. No. 6,106,982 (Mientus et al.), which is incorporated herein by reference.
[0069] The topcoat or overcoat layer may comprise polyolefins, thermoplastic polymers of ethylene or propylene, polyesters, polyurethanes, polyacrylics, polymethacrylics, epoxies, vinyl acetate homopolymers, copolymers or terpolymers, ionomers, and mixtures thereof.
[0070] The transparent topcoat or overcoat may contain UV light absorbers and / or other light stabilizers. Suitable UV light absorbers include those available from BASF under the tradenames "Tinuvin" and "Chimassorb," such as Tinuvin 111, Tinuvin 123, Tinuvin 622, Tinuvin 770, Tinuvin 783, Chimassorb 119, and Chimassorb 944. The concentration of the UV light absorber and / or light stabilizer ranges up to about 2.5% by weight of the transparent or non-transparent protective layer, and in one embodiment, from about 0.05% to about 1% by weight. However, in some embodiments, the transparent topcoat or overcoat does not contain any UV light absorbers or stabilizers.
[0071] The permeable topcoat or overcoat layer may contain an antioxidant. Any antioxidant useful in making thermoplastic films can be used.
[0072] According to one embodiment, an exemplary label comprises a clear, recyclable shrink PET film with an optional antistatic coating, high TD shrinkage, low MD shrinkage, very low shrink force, and a graduated shrink curve. According to one embodiment, the label of the present disclosure can meet certain industry standards, including, for example, the Association for Plastic Recyclers (APR) Critical Guidance Protocol for Clear PET Articles with Labels and Closures (PET-CG-02), which can be considered to certify that the film is fully recyclable along with the container or bottle. In some embodiments, the label of the present disclosure is recyclable according to the Evaluation of the Near Infrared (NIR) Sorting Potential of a Whole Plastic Article (SORT-B-01), the Evaluation of Sorting Potential for Plastic Articles Utilizing Metal, Metalized, or Metallic Printed Components (SORT-B-03), or both. That is, according to one embodiment, the label of the present disclosure is fully recyclable. For example, the label may include ink that can be washed away in a typical PET recycling wash (caustic wash), and the polymer used in the label is preferably transparent (preferably clear PET). According to one embodiment, the label is free or substantially free of ink that cannot be washed away in a caustic wash. According to one embodiment, the label is free or substantially free of colored plastics (including white plastics) that cannot be recycled.
[0073] High opacity coating composition According to one embodiment, the label comprises a high opacity layer formed from a high opacity coating composition. In some embodiments where a transparent shrink film is used, it may be useful for the disclosed article to comprise an optional high opacity layer applied thereon or on a layer applied on the transparent shrink film. The high opacity layer may be applied by applying a high opacity coating composition to one or more layers of the label.
[0074] Useful high-opacity coating compositions can include aqueous or non-aqueous ink compositions. In some embodiments, the high-opacity coating composition includes a white pigment. Examples of useful white pigments include, for example, titanium dioxide (TiO), precipitated calcium carbonate (PCC), aluminum silicate, aluminum oxide (e.g., alumina), mica-based pigments (such as TiO) coated with a thin layer of white pigment, and combinations thereof.
[0075] In some embodiments, the high opacity coating composition can include a white pigment, an anionic surfactant, latex particles, and a balance of water. In other examples, the high opacity coating composition can include additives such as optical brighteners, biocides, additional surfactants, cosolvents, and / or wetting agents.
[0076] Useful high opacity coating compositions can include, for example, compositions formulated for use as rotogravure inks (e.g., rotogravure solvent-based inks), flexographic inks, lithographic inks, or digital printing inks (e.g., inkjet, nanographic).
[0077] The high-opacity coating composition can be deposited on the shrink film using any method known in the art, including, but not limited to, gravure printing (e.g., rotogravure), flexography, and lithography (e.g., offset lithography), plateless printing (e.g., digital), post-press application, and screen printing. Gravure printing involves the direct transfer of liquid ink from a metal image carrier to a substrate. The image is lower than the surface of the image carrier base. Flexography is typically the direct transfer of liquid ink from a photopolymer image carrier to a substrate, although other image carriers exist. The image is raised above the surface of the image carrier base. Offset lithography is the indirect transfer of paste ink to a substrate from a rubber "blanket" intermediate the substrate and a thin, lithographic metal image carrier. Some examples of plateless printing include liquid toner electrophotography, dry toner electrophotography, drop-on-demand inkjet, continuous inkjet, or NANOGRAPHY™.
[0078] In embodiments in which the high opacity coating composition is applied to a shrink film or a layer on a shrink film by rotogravure coating or printing, the high opacity coating composition can have a viscosity of from 16 seconds to 40 seconds, from 16 seconds to 25 seconds, or from 19 seconds to 24 seconds, as measured, for example, with a No. 2 Zahn cup.
[0079] In embodiments in which the high opacity coating composition is applied to a shrink film or a layer on a shrink film via gravure coating or rotogravure coating, the high opacity coating composition can be applied using one or more rotogravure cylinders. The cylinders may be adjusted to provide a desired amount of coating composition on the surface of the shrink film or layer. The cylinders may have a cell volume of 1.0 BCM or more, 5 BCM or more, 10 BCM or more, or 15 BCM or more. The cell volume may be 2 BCM or less, 25 BCM or less, or 20 BCM or less. The cell volume may be in a range of, for example, 1.0 BCM to 30.0 BCM, or 5 BCM to 25 BCM. The cylinders may have a cell width value of 25 μm or more, 50 μm or more, or 100 μm or more. The cylinders may have a cell width value of 300 μm or less, 250 μm or less, or 200 μm or less. The cell width value may be in a range of, for example, 25 μm to 300 μm. The cylinder may have a channel width of 1 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or 30 μm or more. The channel width may be 75 μm or less or 50 μm or less. The channel width may be in the range of 1 μm to 75 μm. The cylinder may have a line screen value of 25 LPI or more, 50 LPI or more, 100 LPI or more, 150 LPI or more, or 200 LPI or more. The line screen value may be 400 LPI or less, 350 LPI or less, 300 or less, 250 or less, or 200 or less. The line screen value may be in the range of 25 LPI to 400 LPI. According to exemplary embodiments, the desired dry coating weight may be 0.5 ppr or more, 1 ppr or more, 5 ppr or more, 10 ppr or more, or 15 ppr or more. The desired dry coating weight may be 25 ppr or less, 20 ppr or less, or 15 ppr or less. The desired dry coating weight may range from 0.5 ppr to 25 ppr.
[0080] Application of the high opacity coating composition onto the shrink film or onto a layer on the shrink film forms a high opacity layer. The high opacity layer need not be uniform, continuous, or complete across the entire shrink film. In some embodiments, the high opacity layer forms a pattern of discrete dots of ink. In other embodiments, the high opacity layer forms a continuous layer of ink.
[0081] light shielding layer According to one embodiment, the label comprises a layer of light-blocking material, such as a light-blocking ink. The light-blocking material may be applied onto the shrink film or onto a layer applied onto the shrink film, such as the high opacity layer described above. The light-blocking material may be applied in the form of a light-blocking composition that includes one or more light-blocking components.
[0082] According to one embodiment, a label comprising a light-blocking layer blocks at least 80%, at least 90%, at least 95%, at least 96%, at least 98%, at least 99%, or even nearly 100% or 100% of incident light having a wavelength between 200 nm and 900 nm. According to one embodiment, a label comprising a light-blocking layer blocks at least 95%, at least 96%, at least 98%, at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength between 220 nm and 800 nm. According to one embodiment, a label comprising a light-blocking layer blocks at least 98%, at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength between 220 nm and 750 nm. According to one embodiment, a label with a light-blocking layer blocks at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength between 220 nm and 600 nm. According to one embodiment, a label with a light-blocking layer blocks at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength between 220 nm and 500 nm. According to one embodiment, a label with a light-blocking layer blocks at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength between 220 nm and 450 nm. The amount of light blocked by the label can be measured using a UV-Vis spectrophotometer, such as a Shimadzu model UV-2600i.
[0083] According to one embodiment, the label includes a light-blocking layer containing one or more light-blocking components. In some embodiments, the light-blocking component includes one or more metals. In some embodiments, useful light-blocking components can include pigments encapsulated with metals or metal-containing compounds. Examples of light-blocking components include, but are not limited to, organic and inorganic pigments designed for solvent printing or water-based printing, such as metallic pigments. The pigments can be encapsulated or unencapsulated. Useful metallic pigments can include, for example, zinc, copper, silver, aluminum, and alloys and combinations thereof. In other embodiments, the light-blocking component includes titanium dioxide and related fillers, carbon black, mica, reflective pigments, and other polymers and minerals capable of blocking light.
[0084] According to one embodiment, the light-blocking component is a particulate material. The particles of the light-blocking component may have a particle size of 0.1 μm or more, 0.5 μm or more, 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more. The particle size of the light-blocking component particles may be 100 μm or less, 50 μm or less, 25 μm or less, 15 μm or less, 12 μm or less, 10 μm or less, 8 μm or less, 7 μm or less, or 6 μm or less. In some embodiments, the particle size of the light-blocking component is within the range of 0.1 μm to 100 μm, 1 μm to 50 μm, or 2 μm to 25 μm. The particle size here refers to an average particle size measured by laser diffraction.
[0085] Useful light-blocking coating compositions can include, for example, compositions formulated for use as rotogravure inks (e.g., rotogravure solvent-based inks), flexographic inks, lithographic inks, or digital printing inks (e.g., inkjet, nanographic).
[0086] In addition to the light-blocking component, the light-blocking composition may further include a solvent such as an alcohol, ester, ketone, or hydrocarbon mixture; a resin such as nitrocellulose, polyamide, vinyl, or acrylic; or additives such as waxes, plasticizers, surfactants, corrosion inhibitors, or crosslinking agents to adjust the properties of the composition.
[0087] The amount of light-blocking component in the light-blocking composition may be 3.0 wt% or more, 5.0 wt% or more, or 10 wt% or more. The amount of light-blocking component in the light-blocking composition may be 50.0 wt% or less, 40 wt% or less, 30 wt% or less, or 25 wt% or less. The amount of light-blocking component in the light-blocking composition may be 3.0 wt% to 50 wt%, 5.0 wt% to 40 wt%, or 10 wt% to 25 wt%. The amount of light-blocking component on the label may vary based on the desired amount of light-blocking and the particular light-blocking component used. In some embodiments, the light-blocking component may be present on the label at 0.1 ppr to 10 ppr, 0.2 ppr to 5 ppr, or 0.3 ppr to 3 ppr.
[0088] The light-blocking coating composition can be applied to the shrink film (or to a layer thereon) using any method known in the art, including, but not limited to, gravure printing (e.g., rotogravure printing), flexography, and lithography (e.g., offset lithography), plateless printing (e.g., digital), post-press application, and screen printing. Gravure printing involves the direct transfer of liquid ink from a metal image carrier to a substrate. The image is lower than the surface of the image carrier base. Flexography is typically the direct transfer of liquid ink from a photopolymer image carrier to a substrate, although other image carriers exist. The image is raised above the surface of the image carrier base. Offset lithography is the indirect transfer of paste ink to a substrate from a rubber "blanket" intermediate the substrate and a thin, lithographic metal image carrier. Some examples of plateless printing include liquid toner electrophotography, dry toner electrophotography, drop-on-demand inkjet, continuous inkjet, or NANOGRAPHY™.
[0089] In embodiments in which the light-blocking coating composition is applied to a shrink film or a layer on a shrink film by rotogravure coating or printing, the light-blocking coating composition can have a viscosity of 16 seconds or more, 17 seconds or more, 18 seconds or more, or 19 seconds or more, as measured with a No. 2 Zahn cup. The viscosity may be 40 seconds or less, 25 seconds or less, or 24 seconds or less. For example, the viscosity may range from 16 seconds to 40 seconds, from 15 seconds to 25 seconds, or even from 19 seconds to 24 seconds.
[0090] The light-blocking composition may be applied to the label at a speed suitable for achieving the desired light-blocking performance. When gravure coating or rotogravure coating is used, the amount of composition used may be controlled by adjusting the engraving specifications of the gravure cylinder. The cylinder may have a cell volume of 1.0 BCM or more, 5 BCM or more, 10 BCM or more, or 15 BCM or more. The cell volume may be 2 BCM or less, 25 BCM or less, or 20 BCM or less. The cell volume may be in the range of, for example, 1.0 BCM to 30.0 BCM, or 5 BCM to 25 BCM. The cylinder may have a cell width value of 25 μm or more, 50 μm or more, or 100 μm or more. The cylinder may have a cell width value of 300 μm or less, 250 μm or less, or 200 μm or less. The cell width value may be in the range of, for example, 25 μm to 300 μm. The cylinder may have a channel width of 1 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or 30 μm or more. The channel width may be 75 μm or less or 50 μm or less. The channel width may be in the range of 1 μm to 75 μm. The cylinder may have a line screen value of 25 LPI or more, 50 LPI or more, 100 LPI or more, 150 LPI or more, or 200 LPI or more. The line screen value may be 400 LPI or less, 350 LPI or less, 300 or less, 250 or less, or 200 or less. The line screen value may be in the range of 25 LPI to 400 LPI. According to exemplary embodiments, the desired dry coating weight may be 0.1 ppr or more, 0.2 ppr or more, 0.3 ppr or more, 0.4 ppr or more, 0.5 ppr or more, 1 ppr or more, 5 ppr or more, 10 ppr or more, or 15 ppr or more. The desired dry coating weight may be 25 ppr or less, 20 ppr or less, or 15 ppr or less. The desired dry coating weight may range from 0.1 ppr to 25 ppr, 0.4 ppr to 15 ppr, or 0.5 ppr to 10 ppr.
[0091] In embodiments, the light-blocking coating composition may be applied to a shrink film or a layer on a shrink film via rotogravure coating or printing using a single (1) rotogravure cylinder having a line screen number ranging from 25 LPI to 400 LPI. In some embodiments, the light-blocking coating composition may be applied to a shrink film or a layer on a shrink film via rotogravure coating using a single (1) rotogravure cylinder having a line screen number of 120 LPI or two (2) rotogravure cylinders having a line screen number of 200 LPI. The resulting dry coating weight may be in the range of 0.5 ppr to 10 ppr.
[0092] The application of a light-blocking coating composition onto the shrink film or onto a layer on the shrink film forms a light-blocking layer. The light-blocking layer need not be uniform, continuous, or complete across the entire shrink film. In some embodiments, the high opacity layer forms a pattern of discrete dots of the light-blocking component. In other embodiments, the high opacity layer forms a continuous layer of the light-blocking component.
[0093] Mark layer The disclosed labels may also include an indicia layer applied thereto or over a layer applied to the shrink film, such as over the high opacity layer described above. The indicia layer can be applied by applying one or more layers or one or more partial layers of an imaging composition.
[0094] Useful imaging compositions can include, for example, compositions formulated for use as rotogravure inks (e.g., rotogravure solvent-based inks), flexographic inks, lithographic inks, or digital printing inks (e.g., inkjet, nanographic). Virtually any ink or combination of ink compositions useful for forming indicia (e.g., images and associated text for forming product labels) can be utilized to form the indicia layer as disclosed herein.
[0095] Suitable components of the image-forming composition are not particularly limited. Some examples of suitable components that can be used in the image-forming composition are disclosed below.
[0096] In some embodiments, the imaging composition includes a solvent, such as an organic solvent or water, or a combination thereof. The amount of solvent in the composition may be adjusted to provide a desired color strength and viscosity (e.g., as measured using a calibrated No. 2 Zahn cup).
[0097] The imaging composition may contain any suitable inorganic or organic pigment. Examples of inorganic pigments include titanium dioxide, chrome yellow, molybdenum orange, iron blue, cadmium yellow, mirolibrine, ultramarine blue, calcium carbonate, magnesium carbonate, silica aerogel, and kaolin. Examples of organic pigments include Hansa yellow, lamp black, phthalocyanine, Red Lake C, diarylide yellow, phloxine, channel black, and rhodamine. Typical amounts of pigments in gravure printing ink compositions may range from 1% to 20% by weight.
[0098] The imaging composition may include a binder resin such as polyamide, nitrocellulose, shellac, a vinyl polymer, a rosin ester, or an acrylic polymer.
[0099] The imaging composition can be disposed on the shrink film (or on a layer thereon) using any method known in the art, including, but not limited to, gravure printing (e.g., rotogravure), flexography, and lithography (e.g., offset lithography), plateless printing (e.g., digital), post-press application, and screen printing. Gravure printing involves the direct transfer of liquid ink from a metal image carrier to a substrate. The image is lower than the surface of the image carrier base. Flexography is typically the direct transfer of liquid ink from a photopolymer image carrier to a substrate, although other image carriers exist. The image is raised above the surface of the image carrier base. Offset lithography is the indirect transfer of paste ink to a substrate from a rubber "blanket" intermediate the substrate and a thin, lithographic metal image carrier. Some examples of plateless printing include liquid toner electrophotography, dry toner electrophotography, drop-on-demand inkjet, continuous inkjet, or NANOGRAPHY™.
[0100] Application of the imaging composition onto the shrink film or onto a layer on the shrink film forms an indicia layer that does not need to be uniform, continuous, or complete across the entire shrink film.
[0101] The indicia layer may be an ink or graphics layer, and may be a single-color or multi-color print layer depending on the printed message and / or intended pictorial design. These include variable imprint data such as serial numbers, bar codes, and trademarks. The thickness of the indicia layer typically ranges from about 0.5 to about 10 μm, and in one embodiment, from about 1 to about 5 μm, and in another embodiment, about 3 μm. Inks used in the indicia layer may include commercially available water-based, solvent-based, oil-based, or energy-curable inks. Examples of commercially available inks include INXFlex Contour (an INX product identified as an energy-curable ink for shrink sleeve applications), Genesis GS (an INX product identified as a gravure solvent-based ink for shrink sleeve and roll-fed applications), FlexiTech Shrink-U (a Flint Group product identified as a flexographic solvent-based ink for shrink sleeve applications), or PluriTech Shrink-U (a Flint Group product identified as a gravure solvent-based ink for shrink sleeve applications).
[0102] In one embodiment, the indicia layer may comprise a polyester / vinyl ink, a polyamide ink, an acrylic ink, and / or a polyester ink. The indicia layer may be formed by conventional methods, such as, for example, by rotogravure, flexographic, or lithographic printing processes, with the ink composition comprising a resin of the type described above, a suitable pigment or dye, and one or more suitable volatile solvents, on one or more desired areas of the shrink film or layer formed thereon. After application of the indicia-forming composition, the volatile solvent component of the ink composition evaporates, leaving only the non-volatile ink components to form the indicia layer.
[0103] The total amount of ink on the label depends on the graphics (indicia) layer, background (e.g., white) layer, and light-blocking layer. The total amount of ink may be 0.5 ppr or more, 1 ppr or more, 5 ppr or more, 10 ppr or more, or 15 ppr or more. The total amount of ink may be 30 ppr or less, 25 ppr or less, 20 ppr or less, or 15 ppr or less. The total amount of ink may range from 0.5 ppr to 30 ppr.
[0104] Articles and containers 1A shows an article 10 (e.g., a bottle or other container) having a heat-shrinkable label 100 applied to an exterior surface thereof. The heat-shrinkable label 100 comprises a heat-shrinkable film 120 having an indicia layer 125 (e.g., graphics) disposed on one surface thereof, and an opposing surface including a high opacity layer 110 and a light-blocking layer 115 on the high opacity layer 110. In this embodiment, the light-blocking layer 115 is closest to the article to which the heat-shrinkable label 100 is applied.
[0105] 1B shows an article 10 (e.g., a bottle or other container) having a heat-shrinkable label 101 applied to its exterior surface. The heat-shrinkable label 101 comprises a heat-shrinkable film 120 having a light-blocking layer 115 disposed on one surface and a high-opacity layer 110 on the opposite surface. An indicia layer 125 is disposed on the surface of the high-opacity layer 110 opposite the heat-shrinkable film 120. In this embodiment, the light-blocking layer 115 is closest to the article to which the heat-shrinkable label 101 is applied.
[0106] 1C shows an article 10 (e.g., a bottle or other container) having a heat-shrink label 102 applied to its exterior surface. The heat-shrink label 102 comprises a heat-shrink film 120 having an indicia layer 125 disposed on its surface, a high-opacity layer 110 disposed on the surface of the indicia layer 125, and a light-blocking layer 115 disposed on the high-opacity layer 110. In this embodiment, the light-blocking layer 115 is closest to the article 10 to which the heat-shrink label 102 is applied.
[0107] 1D shows an article 10 (e.g., a bottle or other container) having a heat-shrink label 103 applied to its exterior surface. The heat-shrink label 103 comprises a heat-shrink film 120 having a light-shielding layer 115 disposed on one surface and an indicia layer 125 disposed on the opposite surface. In this embodiment, the light-shielding layer 115 is closest to the article 10 to which the heat-shrink label 103 is applied. Such an embodiment may be useful, for example, in situations where a dark or black background on the printed label is acceptable or desirable.
[0108] 1E shows an article 10 (e.g., a bottle or other container) having a heat-shrinkable label 104 applied to its exterior surface. The heat-shrinkable label 104 comprises a heat-shrinkable film 120 having an indicia layer 125 disposed on its surface, and a light-blocking layer 115 disposed on the surface of the indicia layer 125. In this embodiment, the light-blocking layer 115 is closest to the article 10 to which the heat-shrinkable label 104 is applied.
[0109] It should also be noted that additional layers not shown in these embodiments, including tie layers, adhesive layers, primer layers, etc., may optionally be included between or adjacent to any of the layers shown.
[0110] The article or container to which the label is applied may be provided in a variety of forms or shapes. Non-limiting examples of suitable articles include containers with and without closures, such as bottles, jars, tubes, trays, lids, toys, and appliances. An exemplary article 1 is shown in FIG. 2. The article 1 comprises a container 10 (e.g., a bottle) defining an outer surface 11. A recyclable shrink label 100′ according to an embodiment of the present disclosure is disposed on the outer surface 11. A first side of the recyclable shrink label 100′ faces the container 10, and a second side 150 faces outward. The article or container may be made from any polymer (e.g., a conventional polymer or a biopolymer), glass, or a metal such as aluminum. Examples of suitable polymeric materials include high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET), polypropylene (PP), polylactic acid (PLA), polyvinyl chloride, polycarbonate, nylon, fluorinated ethylene propylene, polystyrene, and the like. The article or container may be made from a recyclable material. The article or container may be made from the same or similar polymer as the label, for example, PET. The article or container can be made by many different processes known in the art, such as blow molding, injection molding, thermoforming, rotational molding, etc.
[0111] Useful containers include, for example, bottles with closures, tubes with closures, jars, and the like. In some embodiments, useful beverage containers may include one or more recyclable synthetic pigments and / or resins. Preferably, the containers may be processed in existing recycling streams, such as mechanical PET recycling streams. Non-limiting examples of suitable pigments and / or resins include, but are not limited to, high melting point PET fines; PET comonomers; reactants or by-products of PET polymerization; polyethylene naphthalate (PEN); terephthalic acid (TPA or PTA); bis(hydroxyethyl) terephthalate (BHET); dimethyl terephthalate (DMT); dimethyl-2,6 naphthalenedicarboxylate (NDC); and isophthalic acid (IPA).
[0112] The container or article may have a transparent appearance. In one embodiment, the container or article has a translucent appearance. The translucent appearance can be achieved, for example, by treating the transparent container or article, adding ingredients such as dyes and pearlescent agents to the base polymer, or using polypropylene and / or polyethylene mixed with a clarifying agent. Treatments include, for example, spray coating, sandblasting, and mold surface treatments.
[0113] In one embodiment, continuous roll labels according to embodiments of the present disclosure can be applied to articles or containers in an automated labeling line process. The automated labeling line process may have a line speed of at least 10 units / minute, at least 25 units / minute, at least 50 units / minute, at least 100 units / minute, or at least 250 units / minute. While there is no desirable upper limit, in practice, the automated labeling line process may have a line speed of up to 2000 units / minute, e.g., up to 500 units / minute, up to 600 units / minute, up to 700 units / minute, up to 800 units / minute, up to 900 units / minute, or up to 1000 units / minute.
[0114] The present invention is defined in the claims. However, below is provided a non-exhaustive list of non-limiting exemplary aspects. Any one or more of the features of these aspects may be combined with any one or more features of another example, embodiment, or aspect described herein.
[0115] According to one exemplary embodiment, a transparent shrink film (e.g., a transparent PET shrink film) having a thickness ranging from (for example) 15 μm to 100 μm, 20 μm to 80 μm, or 25 μm to 70 μm is formed from a wide master roll. The process provides the correct width for production order material size requirements. Typically, artwork is printed repeatedly across the web width of the film to maximize the total number of labels printed from each roll. A slitting step allows the film to be converted to the correct width for the splicing process. The shrink film can be printed using (for example) a rotogravure press with (for example) solvent-based inks. Light-blocking inks can be printed on either side of the film at one or more printing stations. An optional high-opacity coating layer can also be applied to either side of the film along with the light-blocking layer to provide a white, opaque background for the label artwork or graphics provided on the indicia layer. When a transparent film is used, graphics can be printed directly onto the film, followed by a high-opacity layer (e.g., white ink) and then the light-blocking layer. The graphics are visible through the transparent film and are protected by it. Alternatively, the graphics may be printed on a white opaque background. When graphics are printed using a rotogravure press, they are typically printed repeatedly across a web of film, which is then slit into individual label rolls. Any number of colors can be printed, with each color having its own printing cylinder and inking station for applying different inks, colors, and / or coatings. The ink is then dried at each printing station with hot air convection blowers. Line screens ranging from 25 LPI or higher up to 300 LPI are available for rotogravure printing. Viscosity readings in the range of 16 to 28, measured using a No. 2 Zahn cup, are typical for the ink. The light-blocking layer may be a solvent- or water-based composition diluted with known solvents and / or additives to achieve the desired viscosity for the specific printing process.In some embodiments, multiple engravings can be used on both the light-blocking layer and the high-opacity layer (if utilized) to provide the desired ink coverage at commercial printing speeds of 100 meters / minute to 300 meters / minute. All layers, including the high-opacity and light-blocking layers, can be shrunk with a shrink film to ensure adequate adhesion and color density after undergoing the shrinking process. The layers preferably can pass an adhesion tape test using the tape type recommended for the ink system, a Sutherland Ink rub tester of more than 100 rubs using a 4 lb block, or both. The light-blocking layer is typically designed to have a low dynamic coefficient of friction (COF), e.g., less than 0.22.
[0116] The printed film can then be converted from the flat roll and formed into a continuous tube by applying a solvent to one side of the film's edge. A splicing machine can fold the solvent-coated edge side of the film over the non-solvent-coated edge, creating a chemical bond between the two sides and resulting in a continuous tube of film wound into a large roll. Typical splicing speeds can range, for example, from 200 meters per minute up to 500 meters per minute. The spliced / tubular label roll can then be wound into shorter lengths of finished rolls for shipment to customers, e.g., for application onto the intended container. Labels containing light-blocking labels can block at least 80%, at least 90%, at least 95%, at least 96%, at least 98%, at least 99%, or even nearly 100% or 100% of incident light, for example, having wavelengths between 200 nanometers and 900 nanometers.
[0117] According to one embodiment, a method for recycling an article includes determining the type of material (e.g., plastic type) from which the container and recyclable shrink label are made, directing the article to a corresponding recycling stream, and washing the article to remove ink and pigment from the recyclable shrink label. In some cases, the article and label include or are made from PET, can be identified as PET, and can be directed to a PET recycling stream. In other cases, the article and label may include or be made from a different resin and can be directed to a corresponding recycling stream. In some preferred embodiments, the label applied to the article includes or is made from the same resin as the article. The washed article can be transparent and can be free or substantially free from light-blocking components. The article can be washed in a caustic bath. The article can be cut into small pieces before washing. According to one embodiment, during the recycling process, the ink and coating layer cleanly separate from the heat shrink film, allowing the pure resin to be recovered and processed into reusable resin.
[0118] Illustrative Embodiments Embodiment 1 is a recyclable shrink label including: a heat-shrinkable film having a first surface and a second surface opposite the first surface, optionally with a thickness of 15 μm to 100 μm or 30 μm to 80 μm; and a light-shielding layer disposed adjacent to the first surface, the light-shielding layer including a light-shielding component, and configured to block at least 80% of incident light having a wavelength in the range of 200 nm to 900 nm.
[0119] Embodiment 2 is the recyclable shrink label of embodiment 1, further comprising an indicia layer, optionally disposed on the first surface. The indicia layer may be directly adjacent to the first surface. The indicia layer may be directly adjacent to the light-blocking layer. The indicia layer may be disposed between the first surface and another layer, for example, a high-opacity layer.
[0120] Embodiment 3 is a recyclable shrink label of embodiment 1, further comprising a high opacity layer, the high opacity layer optionally comprising a white pigment.
[0121] Embodiment 4 is the recyclable shrink label of embodiment 3, wherein the high opacity layer is disposed between the indicia layer and the light-blocking layer. The high opacity layer may be directly adjacent to the indicia layer. The high opacity layer may be directly adjacent to the light-blocking layer.
[0122] Embodiment 5 is the recyclable shrink label of any one of embodiments 1 to 4, wherein the heat shrink film comprises polyester, polyolefin, or a combination thereof.
[0123] Embodiment 6 is the recyclable shrink label of any one of embodiments 1 to 5, wherein the heat-shrinkable film comprises polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG or PET-G), polyvinyl chloride (PVC), polystyrene or oriented polystyrene (OPS), polylactic acid (PLA), polypropylene (PP), polyethylene (PE), or a combination thereof. The heat-shrinkable film may be composed of polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG or PET-G), polyvinyl chloride (PVC), polystyrene or oriented polystyrene (OPS), polylactic acid (PLA), polypropylene (PP), polyethylene (PE), or a combination thereof. The heat-shrinkable film may be composed of only one of polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG or PET-G), polyvinyl chloride (PVC), polystyrene or oriented polystyrene (OPS), polylactic acid (PLA), polypropylene (PP), and polyethylene (PE). The heat shrink film may be made of polyethylene terephthalate (PET).
[0124] Embodiment 7 is the recyclable shrink label of any one of embodiments 1 to 6, wherein the heat shrink film includes a seam.
[0125] Embodiment 8 is the recyclable shrink label of any one of embodiments 1 to 7, wherein the heat shrink film is in the form of a sleeve or tube. The heat shrink film may be configured to fit over a bottle.
[0126] Embodiment 9 is the recyclable shrink label of any one of embodiments 1 to 8, wherein the heat shrinkable film shrinks or contracts by about 1% to about 90% when heated to 100°C. The heat shrinkable film can shrink by 1% or more, 2% or more, 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more of its size before heating. When heated to 100°C, the heat shrinkable film can shrink by 90% or less, 80% or less, 75% or less, or 70% or less of its size before heating. The heat shrinkable film may shrink in the transverse direction.
[0127] Embodiment 10 is the recyclable shrink label of any one of embodiments 1 to 9, wherein the entire recyclable shrink label shrinks or contracts by about 1% to about 90% when heated to 100° C. The entire recyclable shrink label may shrink in the cross direction.
[0128] Embodiment 11 is the recyclable shrink label of embodiment 1, wherein the high opacity layer comprises a pigment selected from titanium dioxide (TiO), precipitated calcium carbonate (PCC), aluminum silicate, aluminum oxide (alumina), a mica-based pigment coated with a thin layer of white pigment, or a combination thereof.
[0129] Embodiment 12 is the recyclable shrink label of any one of embodiments 1 to 11, wherein the light-blocking component comprises metal microparticles, and optionally, the metal microparticles have a particle size of 0.1 μm to 100 μm.
[0130] Embodiment 13 is the recyclable shrink label of any one of embodiments 1-12, wherein the light-blocking component comprises zinc, aluminum, copper, silver, or alloys thereof, titanium dioxide, carbon black, mica, a reflective pigment, a polymer capable of blocking light, a mineral capable of blocking light, or a combination thereof. The light-blocking component may comprise an aluminum-based component.
[0131] Embodiment 14 is the recyclable shrink label of any one of embodiments 1-13, wherein the light-blocking layer is present in an amount of 0.5 ppr to 25 ppr. The light-blocking layer may have a dry coating weight of 0.1 ppr or more, 0.2 ppr or more, 0.3 ppr or more, 0.4 ppr or more, 0.5 ppr or more, 1 ppr or more, 5 ppr or more, 10 ppr or more, or 15 ppr or more. The dry coating weight may be 25 ppr or less, 20 ppr or less, or 15 ppr or less. The dry coating weight may range from 0.1 ppr to 25 ppr, 0.4 ppr to 15 ppr, or 0.5 ppr to 10 ppr.
[0132] Embodiment 15 is the recyclable shrink label of any one of embodiments 1 to 14, wherein the light-blocking layer contains 0.1 ppr to 10 ppr, 0.2 ppr to 5 ppr, or 0.3 ppr to 3 ppr of the light-blocking component.
[0133] Embodiment 16 is the recyclable shrink label of any one of embodiments 1 to 15, wherein the label including the light-blocking layer blocks at least 80%, at least 90%, at least 95%, at least 96%, at least 98%, at least 99%, or even nearly 100% or 100% of incident light having a wavelength between 200 nm and 900 nm. The label including the light-blocking layer can block at least 95%, at least 96%, at least 98%, at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength between 220 nm and 800 nm. The label including the light-blocking layer can block at least 98%, at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength between 220 nm and 750 nm. A label with a light-blocking layer can block at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength of 220 nm to 600 nm. A label with a light-blocking layer can block at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength of 220 nm to 500 nm. A label with a light-blocking layer can block at least 99%, at least 99.5%, about 100%, or 100% of incident light having a wavelength of 220 nm to 450 nm.
[0134] Embodiment 17 is an article comprising a container including an exterior surface; and the recyclable shrink label of any one of embodiments 1-16 disposed on the container, optionally with a first surface facing the exterior surface of the container.
[0135] Embodiment 18 is the article of embodiment 17, wherein the container comprises a polymer, glass, metal, or a combination thereof.
[0136] Embodiment 19 is the article of any one of embodiments 16-18, wherein the container comprises polyethylene terephthalate (PET), optionally wherein the container consists of polyethylene terephthalate (PET), optionally wherein the container comprises transparent polyethylene terephthalate (PET).
[0137] Embodiment 20 is the article of any one of embodiments 16-19, wherein the recyclable shrink label comprises polyethylene terephthalate (PET), and optionally, the polyethylene terephthalate (PET) forms an outermost layer of the recyclable shrink label.
[0138] Embodiment 21 is the article of any one of embodiments 16-20, wherein the container and the recyclable shrink label comprise the same material. The container and the recyclable shrink label may comprise polyethylene terephthalate (PET).
[0139] Embodiment 22 is a method for making a label for a container, comprising the steps of depositing an indicia layer on a heat-shrinkable film, optionally depositing a high-opacity layer on the indicia layer, and depositing a light-blocking composition on the indicia layer, the heat-shrinkable film, or the high-opacity layer, wherein the light-blocking layer comprises one or more light-blocking components, and the light-blocking layer is capable of blocking at least 80% of incident light having a wavelength in the range of 200 nm to 900 nm.
[0140] Embodiment 23 is a method for recycling an article, the article comprising: a container defining an exterior surface; and a recyclable shrink label according to any one of embodiments 1 to 16 disposed on the container, optionally with a first surface facing the exterior surface of the container, the method comprising: determining that the container and the recyclable shrink label comprise polyethylene terephthalate (PET); directing the article to a polyethylene terephthalate (PET) recycling stream; and washing the article to remove ink and pigment from the recyclable shrink label.
[0141] Embodiment 24 is the method of embodiment 23, wherein the cleaned article is clear and not soiled with light-blocking ingredients or other pigments or inks.
[0142] Embodiment 25 is the method of embodiment 24, wherein washing comprises washing in a caustic bath.
[0143] Embodiment 26 is the recyclable shrink label of any one of embodiments 1-16, further comprising an additional layer including an additional polymer layer, an additional indicia layer, an adhesive layer, a slip coat, a protective top layer, another functional layer, or a combination thereof.
[0144] The present invention is illustrated by the following examples, it being understood that the particular examples, materials, amounts, and procedures are to be interpreted broadly in accordance with the scope and spirit of the invention described herein.
[0145] Objects and advantages of the present disclosure are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit the present disclosure.
[0146] Unless otherwise stated, all parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight. These abbreviations are used in the following examples: g = grams, min = minutes, hr = hours, mL = milliliters, L = liters. Unless otherwise indicated in the tables below, chemicals were obtained from Sigma-Aldrich (St. Louis, MO). [Example]
[0147] Example 1 Exemplary articles were made as shown in Table 1A below. Samples were tested for light blocking ability at wavelengths of 400 nm, 500 nm, 600 nm, and 700 nm using a UV-Vis spectrophotometer (Shimadzu model UV-2600i). Samples were tested before shrinkage. Samples 6 and 7 were also tested after shrinkage. The results are shown in Table 1B.
[0148] The first and second layers were high-opacity layers printed using white ink. The third layer contained white ink, and for samples 1 to 3, also contained blue ink. The fourth and fifth layers were light-blocking layers. The light-blocking component was metal microparticles that exhibited a bronze color.
[0149] [Table 1]
[0150] [Table 2]
[0151] Figures 3-5 show the UV-Vis spectra of the samples. Figure 3 shows the transmittance of each sample in Table 1B. Figure 4 shows a close-up of the bottom portion of Samples 2-7. Figure 5 compares Samples 6 and 7 (before shrinkage) with the 6-shrink and 7-shrink samples.
[0152] Example 2 To evaluate the effect of color on light blocking and the effect of the light blocking layer on color appearance, samples with various color graphics were prepared.
[0153] Samples were prepared using APR certified recyclable 40 μm clear PET shrink sleeve film. Ink was printed onto the film using solvent rotogravure ink. The film was first printed with a single color (yellow, red, or reflective blue). The printed color was then covered with three layers of white ink. On top of the white ink layer, a light-blocking composition was applied at 12 BCM (billion cubic microns per square inch, or 10 9 μm 3 / inch 2 The coating was applied by a rotogravure cylinder with a volume of 1000 .mu.m.
[0154] The samples were tested for their light-blocking ability (before shrinkage) in the wavelength range of 220 nm to 900 nm using a UV-Vis spectrophotometer (Shimadzu model UV-2600i). The results are shown in Table 2. The samples were also visually observed to evaluate the effect of the light-blocking layer on color appearance.
[0155] [Table 3]
[0156] Lower L * Value (L * a * b * It was observed that inks with a higher color density (darker colors on the scale) slightly improved light blocking at certain wavelengths (e.g., 600-700 nm). It was also observed that the light blocking composition had an effect on the visual appearance of the color. It was concluded that more saturated or more opaque colors could be used to produce the intended color effect.
[0157] Example 3 The effect of the thickness of the light-blocking layer on the light-blocking ability was evaluated. Various samples were prepared using APR certified recyclable 40 μm clear PET shrink sleeve film. Ink was printed onto the film using solvent rotogravure ink. The film was first printed with three layers of white ink. The thickness ranged from 5 BCM to 12 BCM (billion cubic microns per square inch, or 10 9 μm 3 / inch 2 A "striped" rotogravure cylinder with lanes having volumes ranging from 0.01 to 0.01 mm (each printing lane having a different engraving specification) was used to apply various thicknesses of light-blocking compositions onto the white ink layer. The light-blocking compositions contained metallic light-blocking components with a gray or silver appearance.
[0158] The samples were tested for their light-blocking ability (before shrinkage) in the wavelength range of 220 nm to 900 nm using a UV-Vis spectrophotometer (Shimadzu Model UV-2600i). The results are shown in Table 3. The samples were also visually observed to evaluate the effect of the light-blocking layer on the appearance of the previously printed white layer. The thickness of the light-blocking layer was observed to have an inverse correlation with the brightness of the white color. As the thickness of the light-blocking layer increased, the brightness of the white color decreased. As the thickness of the light-blocking layer decreased, the brightness of the white layer increased.
[0159] [Table 4]
[0160] Example 4 The light-blocking performance of labels prepared according to the present disclosure was compared to commercially available light-blocking labels.
[0161] Sample labels were prepared similarly to Example 3, using a "striped" rotogravure cylinder with engraved lanes at 12 BCM, 10 BCM, 8 BCM, and 6 BCM volumes to apply the light-blocking layer. The comparative samples were two (2) different commercially available white PET films, each printed on one side with black ink using a rotogravure cylinder with a volume of 10 BCM. The comparative samples were non-recyclable.
[0162] The samples were tested as described in Example 3. The results are shown in Table 4.
[0163] [Table 5]
[0164] It was observed that labels according to the present disclosure provided light-blocking properties comparable to commercially available labels when the light-blocking layer was thicker. As the light-blocking layer became thinner, the light-blocking properties decreased, as seen in Example 3.
[0165] By visual comparison, it was observed that the labels according to the present disclosure exhibited better brightness properties.
[0166] Example 5 The light blocking performance of labels prepared according to the present disclosure was compared to comparative labels used to block light and available commercially.
[0167] Sample labels were prepared using APR certified recyclable 40 μm clear PET shrink sleeve film. Ink was printed onto the film using solvent rotogravure ink. The film was first printed with an indicia layer (four different colored inks). The printed indicia layer was then covered with three layers of white ink. A light-blocking composition was applied over the white ink layer at 12 BCM (billion cubic microns per square inch, or 10 9 μm 3 / inch 2 The coating was applied by a rotogravure cylinder with a volume of 1000 .mu.m.
[0168] The comparative samples (Comparative Sample 3 and Comparative Sample 4) were two (2) different printed labels currently used on products that require light blocking to protect their contents. Comparative Sample 3 was printed on white film, had nearly identical graphics to the sample label, and had black printing on the inside to help block light. Comparative Sample 4 was printed on white film, had different graphics than the sample label or Comparative Sample 3, and had black printing on the inside to help block light. The comparative samples are not recyclable.
[0169] The samples were tested as described in Example 3. The shading results are shown in Table 5 below.
[0170] [Table 6]
[0171] Labels according to the present disclosure have been observed to provide light blocking properties comparable to commercially available labels.
[0172] By visual comparison, it was observed that the label according to the present disclosure exhibited better brightness characteristics and the color of the indicia layer appeared more vibrant.
[0173] Example 6 The ability of a typical recycling device to correctly sort bottles labeled according to the present disclosure was tested to test compliance with APR sorting requirements. Samples were tested in accordance with APR Document No. SORT-B-03, "Evaluation of Sorting Potential for Plastic Articles Utilizing Metal, Metalized, or Metallic Printed Components," issued May 15, 2018. Further guidance can be found in APR Documents PET-CG-02, "Critical Guidance Protocol for Clear PET Articles with Labels and Closures"; and PET-B-02, "Benchmark Evaluation for Clear PET Articles with Labels and Closures."
[0174] Labels were prepared as described in Example 2 using a 12 BCM light-blocking layer. The labels were applied onto clear PET bottles. The labeled bottles were tested in the Eriez Xtreme Test Line in both vertical and horizontal orientations. Before testing began, the candidate article was compressed. The article was determined to be ferrous or not. Ferrous articles were tested with a plate magnet. The article was then passed through a tunnel metal detector in both vertical and horizontal orientations, and the spherical equivalent of the sample was calculated. A sphere size of 0-2 mm indicated a recyclable sample.
[0175] The samples were found to exhibit sphere sizes of 0.5 mm in portrait orientation and 0.6 mm in landscape orientation.
[0176] The bottle was also passed through an eddy current sorter and an NIR sorter, which are used to identify PET products. The bottle was recognized as PET by the NIR sorter. The bottle was also not captured by the eddy current sorter. In other words, the bottle passed the recycling standards for plastic (e.g., PET) bottles.
[0177] The complete disclosures of all patents, patent applications, and publications cited herein, as well as electronically available materials, are incorporated by reference. In the event of any inconsistency between the disclosure of this application and the disclosure of any document incorporated herein by reference, the disclosure of this application shall control. The foregoing detailed description and examples are set forth for clarity of understanding only. No unnecessary limitations should be understood therefrom. The invention is not limited to the exact details shown and described, for variations obvious to those skilled in the art will be within the scope of the invention as defined by the claims.
Claims
1. A recyclable shrink label comprising: a heat shrinkable film having a first surface and a second surface opposite the first surface, the heat shrinkable film having a thickness of 15 μm to 100 μm or 30 μm to 80 μm; a light-blocking layer disposed adjacent the first surface, the light-blocking layer comprising a light-blocking component, wherein the recyclable shrink label is configured to block at least 80% of incident light having a wavelength in the range of 200 nm to 900 nm; and A recyclable shrink label comprising:
2. 10. The recyclable shrink label of claim 1 further comprising an indicia layer, optionally disposed on said first surface.
3. 3. The recyclable shrink label of claim 1 or 2, further comprising a high opacity layer, said high opacity layer optionally comprising a white pigment.
4. 4. The recyclable shrink label of claim 3, wherein the recyclable shrink label comprises an indicia layer, and the high opacity layer is disposed between the indicia layer and the light-blocking layer.
5. The recyclable shrink label of any one of claims 1 to 4, wherein the heat shrink film comprises polyester, polyolefin, or a combination thereof.
6. 6. The recyclable shrink label of claim 1, wherein the heat-shrinkable film comprises polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG or PET-G), polyvinyl chloride (PVC), polystyrene or oriented polystyrene (OPS), polylactic acid (PLA), polypropylene (PP), polyethylene (PE), or a combination thereof.
7. The recyclable shrink label of any one of claims 1 to 6, wherein the heat shrink film includes a seam.
8. The recyclable shrink label of any one of claims 1 to 7, wherein the heat shrink film is in the form of a sleeve or tube.
9. 9. The recyclable shrink label of any one of claims 1 to 8, wherein when heated to 100°C, the heat shrink film shrinks or contracts by about 1% to about 90%, and optionally, the heat shrink film shrinks or contracts by about 1% to 90% in the cross direction.
10. 10. The recyclable shrink label of any one of claims 1 to 9, wherein when heated to 100°C, the entire recyclable shrink label shrinks or contracts by about 1% to about 90%, and optionally the entire recyclable shrink label shrinks or contracts by about 1% to 90% in the cross direction.
11. The high opacity layer is made of titanium dioxide (TiO 2 ), precipitated calcium carbonate (PCC), aluminum silicate, aluminum oxide (alumina), a mica-based pigment coated with a thin layer of white pigment, or a combination thereof.
12. The recyclable shrink label of any one of claims 1 to 11, wherein the light blocking component comprises metal particulates, and optionally the metal particulates have a particle size of 0.1 μm to 100 μm.
13. 13. The recyclable shrink label of any one of claims 1 to 12, wherein the light-blocking component comprises zinc, aluminum, copper, silver, or alloys thereof, titanium dioxide, carbon black, mica, a reflective pigment, a polymer capable of blocking light, a mineral capable of blocking light, or a combination thereof.
14. The recyclable shrink label of any one of claims 1 to 13, wherein the light-blocking layer is present in an amount of from 0.5 ppr to 25 ppr.
15. The recyclable shrink label of any one of claims 1 to 14, wherein the light-blocking layer comprises 0.1 ppr to 10 ppr, 0.2 ppr to 5 ppr, or 0.3 ppr to 3 ppr of the light-blocking component.
16. a container including an exterior surface; a recyclable shrink label according to any one of claims 1 to 15 disposed on the container, optionally with the first surface of the heat shrink film facing the outer surface of the container; An article comprising:
17. 17. The article of claim 16, wherein the container comprises a polymer, glass, metal, or a combination thereof.
18. 18. The article of claim 16 or 17, wherein the container comprises polyethylene terephthalate (PET), optionally wherein the container consists of polyethylene terephthalate (PET), optionally wherein the container comprises transparent polyethylene terephthalate (PET).
19. 19. The article of any one of claims 16-18, wherein the recyclable shrink label comprises polyethylene terephthalate (PET), and optionally the polyethylene terephthalate (PET) forms an outermost layer of the recyclable shrink label.
20. 1. A method of making a label for a container, comprising: depositing an indicia layer on the heat shrinkable film; Optionally, depositing a high opacity layer over said indicia layer; depositing a light-blocking composition onto the indicia layer, the heat-shrinkable film, or the high opacity layer; The method, wherein the light-blocking layer comprises one or more light-blocking components, and the label is capable of blocking at least 80% of incident light having a wavelength in the range of 200 nm to 900 nm.
21. 16. A method of recycling an article, the article comprising a container defining an exterior surface, and a recyclable shrink label according to any one of claims 1 to 15 disposed on the container, optionally with the first surface facing the exterior surface of the container, the method comprising: determining that the container and recyclable shrink label comprise polyethylene terephthalate (PET); directing the article to a polyethylene terephthalate (PET) recycling stream; washing the article to remove ink and pigment from the recyclable shrink label; A method comprising:
22. 22. The method of claim 21, wherein the cleaned article is clear and not soiled by the light-blocking component or other pigments or inks.