Foam Compositions, Foam Padded Materials, and Packaging Articles

Abstract

A polymer foam composition, a foam padded material comprising such a polymer foam composition, and a packaging article (e.g., an envelope) comprising such a foam padded material, wherein the foam composition comprises a polymer component comprising a copolymer comprising divalent hydroxyethylene monomer units and divalent dihydroxybutylene monomer units, and wherein the composition is in the form of an at least partially water soluble foam.

Description

[Background technology]

[0001] Existing packaging (e.g., shipping envelopes) come in two general forms, with and without a cushioning layer. Cushioning is an important element of protective packaging. It is known to use closed-cell extruded polystyrene foam or bubble wrapping, such as that available under the trade name BUBBLE WRAP, as a cushioning component in packaging. Such materials cannot be renewable or compostable. Thus, most end up in landfills. Even when they are renewable, it is well-established that plastic products have a much lower rate of recycling than paper-based products. More environmentally friendly approaches to making packaging have been attempted based on cellulosic materials and water-based adhesives, but such packaging materials may not be durable enough to provide suitable properties (e.g., effective insulation, impact protection, and compression resistance). Summary of the Invention

[0002] The present disclosure provides polymeric foam compositions, foam padded materials comprising such polymeric foam compositions, and packaging articles (eg, envelopes) comprising such foam padded materials.

[0003] In one embodiment, a foam composition is provided that includes a polymer component that includes a copolymer that includes divalent hydroxyethylene monomer units and divalent dihydroxybutylene monomer units, the composition being in the form of an at least partially water soluble foam.

[0004] In another embodiment, there is provided a renewable and / or compostable foam padded material comprising a sheet material having first and second major surfaces, the sheet material comprising a renewable material (e.g., paper), and a foam composition disposed on the first major surface of the sheet material, wherein the foam composition is as described herein.

[0005] In yet another embodiment, a packaging article is provided comprising: a first wall having a first inner surface and a first outer surface opposite the first inner surface; a second wall having a second inner surface and a second outer surface opposite the second inner surface, wherein the first and second inner surfaces define an interior of the packaging article and the first and second outer surfaces define an exterior of the packaging article; a foam composition disposed on at least a portion of each of the first and second inner surfaces; and a seal joint at one or more edges of the first and second walls, the seal joint comprising the foam composition and attaching the first wall to the second wall, wherein the first and second walls comprise renewable materials, and the foam composition is as described herein.

[0006] Certain terms in this disclosure are defined below. Other terms are familiar to those of skill in the art and are intended to be given the meanings that those skilled in the art have assigned to them.

[0007] The terms "polymer" and "polymeric material" include, but are not limited to, organic homopolymers, copolymers, such as block copolymers, graft copolymers, random copolymers, and copolymers, terpolymers, and the like, as well as blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term "polymer" is intended to encompass all possible geometric configurations of the material. These configurations include, but are not limited to, isotactic, syndiotactic, and atactic symmetries.

[0008] The term "copolymer" refers to a polymer that contains two or more different monomeric units or segments, including terpolymers, tetrapolymers, and the like.

[0009] The term "compostable" refers to a material, composition, or article that meets the standard ASTM D6400 or ASTM D6868. It should be noted that since these two standards are applicable to different types of materials, a material, composition, or article will usually only meet one of them, the most applicable one, in order to be "compostable" as defined herein. In certain embodiments, the term "compostable" preferably refers to a material, composition, or article that meets the standard ASTM D6400. In particular, a compostable material, composition, or article also meets the ASTM D5338 standard. In particular, a compostable material, composition, or article also meets one or more of the standards EN 13432, AS 4736, AS 5810, or ISO 17088. More particularly, a compostable material, composition, or article also meets the ISO 14855 standard.

[0010] It should be noted that the term "compostable" as used herein is not interchangeable with the term "biodegradable." Something that is "compostable" should degrade within the time specified by the above standards into a material that has toxicity, particularly phytotoxicity, consistent with the above standards. The term "biodegradable" does not specify the time that a material should degrade, nor does it specify that the compound that degrades pass any standard for lack of toxicity or environmental harm. For example, a material that meets the ASTM D6400 standard should pass tests specified in ISO 17088, which addresses the "presence of high levels of regulated metals and other harmful components," while a material that is "biodegradable" may have any level of harmful components.

[0011] The term "recyclable" refers to a material, composition, or article that meets at least one of the following standards: the Voluntary Standard for Repulping and Recycling Corrugated Fiberboard published by the Fibre Box Association (FBA) part 1 (repulpability), the Voluntary Standard for Repulping and Recycling Corrugated Fiberboard published by the Fibre Box Association (FBA) part 2 (recyclability), and the ISO 18601 standard. Certain renewable items meet the Repulping and Recycling Corrugated Fiberboard part 1 (repulpability). Certain renewable items meet the Voluntary Standard for Repulping and Recycling Corrugated Fiberboard part 2 (recyclability). Further, certain renewable items meet the Voluntary Standard for Repulping and Recycling Corrugated Fiberboard part 1 (repulpability) and part 2 (recyclability). Even more specifically, the renewable items meet the Voluntary Standard for Repulping and Recycling Corrugated Fiberboard part 1 (repulpability) and part 2 (renewability) standards, as well as the ISO 18601 standard. Even more specifically, the renewable items further meet the ISO 18604:2013 standard. All references to the Voluntary Standard for Repulping and Recycling Corrugated Fiberboard standard, whether to part 1, part 2, or both, refer to the 2013 version of the standard. It should be noted that renewable materials may include materials, such as adhesives, that do not meet one or more of the above standards.This is because materials, particularly adhesives, are typically removed from paper products during the recycling process. Such materials, particularly adhesives, that are not themselves renewable but are easily removed from the product during the recycling process are referred to herein as "recyclable." Thus, a "recyclable" article may contain components that are renewable as well as components that are compatible with recycling.

[0012] Throughout this disclosure, the singular forms "a," "an," and "the" are often used for convenience, but are intended to include the plural unless expressly stated in the singular or clearly indicated by the context. When referring to the singular only, the term "one and only one" is typically used.

[0013] Terms indicating frequency, such as (but not limited to) "common," "typical," and "ordinary," are used herein to refer to features that are frequently used in this disclosure, and are not intended to imply that the features are present in the prior art, much less that they are common, ordinary, or typical in the prior art, unless specifically used with reference to the prior art.

[0014] As used herein, the term "comprising" and variations thereof do not have a limiting meaning when these terms appear in the specification and claims. Such terms are understood to imply the inclusion of the described step or element or group of steps or elements, but not the exclusion of any other step or element or group of steps or elements. "Consisting of" means to include and be limited to everything before the phrase "consisting of". Thus, the phrase "consisting of" indicates that the recited elements are necessary or mandatory, and that no other elements may be present. "Consisting essentially of" means to include everything before the phrase, and is limited to other elements that do not interfere with or contribute to the activity or action specified in this disclosure with respect to those recited elements. Thus, the phrase "consisting essentially of" indicates that the recited elements are necessary or mandatory, but that other elements are optional and may or may not be present depending on whether they substantially affect the activity or action of the recited elements. Any element or combination of elements described herein with open-ended language (e.g., "comprising" and its derivatives) is considered to be further described with closed-ended language (e.g., "consisting of" and its derivatives) and partially closed-ended language (e.g., "consisting essentially of" and its derivatives).

[0015] The words "preferred" and "preferably" refer to embodiments of the present disclosure that may provide certain benefits, under particular circumstances. However, other claims may also be preferred, under the same or other circumstances. Moreover, the recitation of one or more preferred claims does not imply that other claims are not useful, and is not intended to exclude other claims from the scope of the present disclosure.

[0016] As used herein, the term "or" is generally used in its ordinary sense, including "and / or," unless the content specifically dictates otherwise. The term "and / or" refers to one or all of the listed elements or a combination of any two or more of the listed elements.

[0017] Further, all numbers herein are deemed to be modified by the term "about," and in certain embodiments, preferably, by the term "exactly." As used herein, in the context of a measured quantity, the term "about" refers to the variation in the measured quantity as 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 used. As used herein, a "up to" number (e.g., up to 50) is inclusive of that number (e.g., 50).

[0018] Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range, as well as the endpoints thereof (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0019] The terms "in the range" or "within a range" (and similar descriptions) include the endpoints of the stated range.

[0020] Groupings of alternative elements or embodiments disclosed herein should not be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found in the group. It is anticipated that one or more members of a group may be included in or deleted from a group for reasons of convenience and / or patentability. When any such inclusion or deletion occurs, the specification is deemed herein to include the modified group and thus implements the full recitation of all Markush groups used in the appended claims.

[0021] References throughout this specification to "one embodiment," "an embodiment," "certain embodiment," or "some embodiments" mean that the particular features, configurations, compositions, or characteristics described with respect to the embodiment are included in at least one embodiment of the present invention. Thus, the appearances of such phrases in various places throughout this specification are not necessarily referring to the same embodiment of the present invention. Moreover, the particular features, configurations, compositions, or characteristics may be combined in any suitable manner in one or more embodiments.

[0022] The above "Summary of the Invention" of this disclosure is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more specifically illustrates exemplary embodiments. In several places throughout this application, guidance is provided through the enumeration of examples, which can be used in various combinations. In each instance, the recited items serve only as a representative group and should not be construed as an exclusive enumeration. Thus, the scope of the disclosure should not be limited to the specific exemplary structures described herein, but extends to at least the structures described by the language of the claims, and equivalents of these structures. Any elements expressly described herein as alternatives may be expressly included in or excluded from the claims in any combination as desired. Various theories and possible mechanisms may be discussed herein, but in no event should such discussion be construed as limiting the claimed subject matter. [Brief description of the drawings]

[0023] [Figure 1A] FIG. 2 is a plan view of an exemplary foam padded material. [Figure 1B] FIG. 2 is a plan view of an exemplary foam padded material. [Figure 1C]FIG. 2 is a plan view of an exemplary foam padded material. [Figure 1D] FIG. 2 is a plan view of an exemplary foam padded material. [Figure 1E] FIG. 2 is a plan view of an exemplary foam padded material. [Figure 1F] FIG. 2 is a plan view of an exemplary foam padded material. [Figure 1G] FIG. 2 is a plan view of an exemplary foam padded material. [Diagram 2] 1 is a schematic diagram of an exemplary packaging article. [Diagram 3] FIG. 2 is a schematic diagram of another exemplary packaging article. [Figure 4] FIG. 2 is a schematic diagram of yet another exemplary packaging article. [Diagram 5] FIG. 2 is a schematic diagram of yet another exemplary packaging article having a flap in an open configuration (5). [Figure 6] FIG. 2 is a schematic diagram of yet another exemplary packaging article having flaps in a closed configuration (6). [Figure 7A] 2 is a schematic diagram of another exemplary packaging article having an adhesive portion. [Figure 7B] FIG. 2 is a schematic diagram of yet another exemplary packaging article having two adhesive portions on the flap. [Figure 8A] 1 is a schematic diagram of an exemplary packaging article. [Figure 8B] 1 is a schematic diagram of an exemplary packaging article. [Figure 9A] 1A-1C are plan views of a template used in a screen printing process and a foam padded material formed from such process, respectively. [Figure 9B] 1A-1C are plan views of a template used in a screen printing process and a foam padded material formed from such process, respectively. [Figure 10A] 1A-1D are schematic diagrams of an unwind station and a die coating station, respectively, used in a random element printing process. [Figure 10B]1A-1D are schematic diagrams of an unwind station and a die coating station, respectively, used in a random element printing process. [Figure 11A] 1 is a schematic diagram of an exemplary packaging article. [Figure 11B] 1 is a schematic diagram of an exemplary packaging article. [Figure 11C] 1 is a schematic diagram of an exemplary packaging article. [Figure 12] A 3D printed rotogravure roll with a pattern on its surface. [Figure 13A] FIG. 2 is a schematic diagram of another packaging article. [Figure 13B] FIG. 2 is a schematic diagram of another packaging article. [Figure 14] FIG. 1 is a schematic diagram of a 3D printed rotogravure roll. [Figure 15] FIG. 1 shows the rotogravure cell dimension, which is the diameter d1 of the inscribed circle tangent to the sides of the hexagon drawn by connecting the centers of the individual cells in the rotogravure array. [Figure 16] FIG. 1 is a top view of one embodiment of the present invention having a foaming composition that forms a plurality of foam cells in a patterned array attached to a substrate. [Figure 17] FIG. 17 is a cross-sectional view of the embodiment of FIG. 16, showing that each foam cell includes an outer shell of foam composition and a hollow interior filled with air. [Figure 18] FIG. 17 is a schematic diagram of a mailer made from the embodiment of FIG. 16 having heat sealed seams, where the foam bubbles are compressed and heat sealed together to form a pouch having an interior with a cushioning array of foam bubbles. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The present disclosure provides a polymer foam composition comprising a polymer component comprising a copolymer comprising divalent hydroxyethylene monomer units and divalent dihydroxybutylene monomer units, the composition being in the form of an at least partially water soluble foam.

[0025] Such polymer foam compositions can be used in renewable and / or compostable foam padded materials and packaging articles (e.g., envelopes). The foam padded materials include a sheet material 10 having a first major surface 12 and a second major surface 14 opposite the first major surface, the sheet material including a renewable material and a foam composition 16 described herein disposed on the first major surface 12 of the sheet material.

[0026] Briefly, the packaging article includes a first wall having a first inner surface and a first outer surface opposite the first inner surface, and a second wall having a second inner surface and a second outer surface opposite the second inner surface. The first and second inner surfaces define the interior of the packaging article, and the first and second outer surfaces define the exterior of the packaging article. The packaging article has one or more edges where the first wall is attached to the second wall at a seal joint. Optionally, the article may have at least one opening where the first wall is not attached to the second wall, which is not a requirement, as it is possible to form the packaging article around an object that is disposed within the interior of the packaging article, thereby eliminating the need for an article with an opening. A foam composition as described herein is disposed on at least a portion of each of the first and second inner surfaces. Preferably, the foam composition also forms a seal joint, thereby attaching the first wall of the packaging article to the second wall.

[0027] In certain embodiments, the polymer foam composition, foam padded material, or packaging article is renewable. In certain embodiments, the polymer foam composition, foam padded material, or packaging article is compostable. In certain embodiments, the polymer foam composition, foam padded material, or packaging article is both renewable and compostable.

[0028] Foaming Composition The foam composition is an organic polymer foam, i.e., a composite of a polymer matrix (i.e., polymeric component) and a gas dispersed therein, typically in bubbles or cells. During foam volume expansion, the gas phase is initially dispersed in the continuous polymer phase. Polymer foams can be prepared mechanically (e.g., air dispersion), physically (e.g., by gas injection, bead foaming, expandable microspheres), or chemically (e.g., by using a blowing agent that generates an effective gas by pyrolysis).

[0029] Such foam compositions typically comprise closed cell foams, although open cell foams are also possible, In certain embodiments, the foam comprises closed cells, and optionally has open and / or burst cells.

[0030] The foamed compositions of the present disclosure typically have a density of at least 0.01 grams per cubic centimeter (g / cc) and at most 0.5 g / cc, as measured according to ASTM D3575-14 ("Standard Test Methods for Flexible Cellular Materials Made from Olefin Polymers" using a pycnometer (DELTARANGE Model AG204 manufactured by Mettler-Toledo, LLC, Columbus, Ohio) and density calculated using Archimedes' principle.

[0031] The foam compositions of the present disclosure are at least partially water soluble, preferably 100% water soluble. In the context of foams (i.e., foam compositions), at least partially water soluble foams means that at least 50% of the foam dissolves in water at 130°F (54°C) according to the Water Solubility Test described in the Examples section. In certain embodiments, at least 60%, at least 70%, at least 80%, at least 85%, at least 90%, at least 95% of the foam (i.e., foam composition) dissolves in water at 130°F (54°C) according to the Water Solubility Test described in the Examples section. Such foam compositions include water soluble components, such as one or more polymers, and one or more optional water soluble additives, as described in more detail below.

[0032] The foam compositions (i.e., foams) of the present disclosure are preferably heat-sealable. This means that the foam composition is sufficiently thermoplastic and will liquefy and flow when exposed to thermal energy, mechanical energy, or a combination thereof (e.g., heat sealing, sonic welding) and will resolidify when cooled, thereby providing a seal between two substrate materials having the foam composition disposed therebetween. The sealability of the foam composition can be quantified using the seam strength test described in the Examples section. In certain embodiments, the foam compositions of the present disclosure have a seam strength of at least 1.0 lbf / in.

[0033] The foam compositions (i.e., foams) of the present disclosure are preferably durable. Durability refers to a combination of many factors, including, for example, the strength and internal integrity of the foam, the adhesion of the foam to the substrate as demonstrated by the foam falling off or adhering to paper, the ability of the foam to absorb shock, and the ability of the foam to withstand compression. The durability of the foam composition can be quantified by abrasion resistance tests, as well as compressive strength and energy absorption loss tests, which are described in the Examples section.

[0034] In certain embodiments, the foam composition of the present disclosure has a foam shedding mass loss from Taber abrasion of 30% or less, 20% or less, or 10% or less after 30 cycles of abrasion with a total weight of 1100 grams applied from above according to the Abrasion Resistance Test.

[0035] In certain embodiments, the foamed compositions of the present disclosure have an absorbed energy loss of at least 100 KJ according to the Compressive Strength and Energy Absorption Loss Test. In certain embodiments, the foamed compositions of the present disclosure have an absorbed energy loss of at least 275 KJ according to the Compressive Strength and Energy Absorption Loss Test.

[0036] In certain embodiments, the foamed compositions of the present disclosure have a compressive stress at 50% compression strain of at least 8 kPa according to the Compressive Strength and Energy Absorption Loss Test. In certain embodiments, the foamed compositions of the present disclosure have a compressive stress at 50% compression strain of up to 25 kPa according to the Compressive Strength and Energy Absorption Loss Test.

[0037] In certain embodiments, the polymer component of the foam composition (i.e., the polymer matrix), which may include one or more polymers, is present in an amount of at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, or at least 90 wt%, based on the total weight of the foam composition (i.e., the final (dried) foam, which may include residual water). In certain embodiments, the polymer component of the foam composition, which may include one or more polymers, is present in an amount of up to 99.5 wt%, based on the total weight of the (final) foam composition. The remainder of the foam composition includes gas (e.g., air) dispersed therein, and may also include one or more blowing agents (e.g., expandable microspheres), residues of such blowing agents after the composition is foamed (e.g., expanding microspheres), fillers, and other optional additives, which are described in more detail below. In certain preferred embodiments, the remainder of the foam composition includes gas and expanding microspheres (i.e., the blowing agent residues resulting after the composition is foamed and the expandable microspheres are expanded), as discussed below.

[0038] The polymer component of the foam composition is selected to be foamable, typically at least partially water soluble, and is preferably formed using a water-based polymer or mixture of polymers that provides the foam padded material or packaging article with one or more of the following properties: impact protection, cushioning, insulation, compression resistance, water resistance, recyclability, and / or compostability.

[0039] For foamability, such polymers are generally highly plasticized by water. This allows for efficient foaming, especially when the foaming is provided by the expansion of expandable microspheres upon heating. Water-based polymers are typically prepared by emulsion polymerization using a single grade or a mixture of emulsion polymers, which may be of synthetic or natural origin.

[0040] Preferably, the one or more water-soluble polymers are water-soluble polymers. In the context of a polymer, water-soluble means that at least 90% by weight of the polymer dissolves in water at 130°F (54°C) in a procedure similar to the water solubility test described in the Examples section. In certain embodiments, at least 95% by weight or at least 99% by weight of the water-soluble polymer dissolves in water at 130°F (54°C) in a procedure similar to the water solubility test described in the Examples section.

[0041] In certain embodiments, the polymeric component comprises a copolymer, preferably a water-soluble polymer, comprising a divalent hydroxyethylene monomer unit (i.e., -CH2-CH(OH)-) and a divalent dihydroxybutylene monomer unit (referred to herein as a "hydroxy-ethylene-butylene copolymer"). In certain embodiments, the polymeric component may comprise one or more such hydroxy-ethylene-butylene copolymers (e.g., differing in monomer composition, molecular weight, melt flow index). In a preferred embodiment, the divalent dihydroxybutylene monomer unit is a 3,4-dihydroxybutane-1,2-diyl monomer unit (i.e., the structure [ka] (monomer units).

[0042] Optionally, but typically, the copolymer contains acetoxyethylene divalent monomer units (i.e., the structure [ka] The monomer unit further comprises

[0043] The copolymers can be obtained by copolymerization of vinyl acetate and 3,4-dihydroxy-1-butene followed by partial or complete saponification of the acetoxy groups to form hydroxyl groups. Alternatively, instead of 3,4-dihydroxy-1-butene, a carbonate, e.g. [ka] can also be used. After copolymerization, the carbonate can be hydrolyzed with simultaneous saponification of the acetate groups. In another embodiment, instead of 3,4-dihydroxy-1-butene, a compound of the formula: [ka] Acetals or ketals having the formula: wherein each R is independently hydrogen or alkyl (e.g., methyl or ethyl) can be used. After copolymerization, the carbonate can be hydrolyzed simultaneously with or separately from saponification of the acetate groups. The copolymers can be prepared by known methods or can be obtained, for example, from commercial sources.

[0044] Commercially available water-soluble copolymers include those available under the tradename Nichigo G-Polymer (Nippon Gosei, Osaka), a highly amorphous polyvinyl alcohol believed to have divalent monomer units of hydroxyethylene, 3,4-dihydroxybutane-1,2-diyl, and optionally acetoxyethylene. Nippon Gosei also refers to Nichigo G-Polymer by the chemical name butenediol vinyl alcohol (BVOH). Exemplary materials include Nichigo G-Polymer grades AZF8035W, OKS-1024, OKS-8041, OKS-8089, OKS-8118, OKS-6026, OKS-1011, OKS-8049, OKS-8074P, OKS-1028, OKS-1027, OKS-1109, OKS-1081, and OKS-1083. Exemplary G-Polymers are available from Soarus LLC, Arlington Heights, IL, USA under the trade designation OKS-8074P. These hydroxy-ethylene-butylene copolymers have a degree of saponification of 80 to 97.9 mole percent and are believed to further comprise an alkylene oxide adduct of the polyhydric alcohol containing 5 to 9 moles of alkylene oxide per mole of polyhydric alcohol.

[0045] The hydroxy-ethylene-butylene copolymer is selected to provide foamability, at least partial water solubility, and preferably durability and / or heat sealability to the foam composition. Physical properties of the hydroxy-ethylene-butylene copolymer that may contribute to such performance characteristics include melt flow index, molecular weight, melting temperature, and decomposition temperature.

[0046] In certain embodiments, one or more of the hydroxy-ethylene-butylene copolymers in the polymeric component have a melt flow index (measured at 210° C. with a load of 2.16 kg) of at least 0.1 grams (g) per 10 minutes (min), or at least 0.5 g per 10 minutes. In certain embodiments, one or more of the hydroxy-ethylene-butylene copolymers in the polymeric component have a melt flow index (measured at 210° C. with a load of 2.16 kg) of at most 60 g / 10 min, at most 50 g / 10 min, at most 40 g / 10 min, at most 30 g / 10 min, at most 20 g / 10 min, or at most 10 g / 10 min.

[0047] In certain embodiments, one or more of the hydroxy-ethylene-butylene copolymers in the polymeric component have a melting temperature (as measured by differential scanning calorimetry (DSC)) of at least 90° C., at least 140° C., or at least 155° C. In certain embodiments, one or more of the hydroxy-ethylene-butylene copolymers in the polymeric component have a melting temperature (as measured by DSC) of at most 220° C., at most 200° C., or at most 195° C.

[0048] These hydroxy-ethylene-butylene copolymers may be used alone as the polymeric component of the foam or in combination with other (second) organic polymers, which may or may not be water-soluble.

[0049] In certain embodiments, the one or more hydroxy-ethylene-butylene copolymers are present in the polymeric component in an amount of at least 1 wt%, at least 10 wt%, at least 15 wt%, at least 25 wt%, at least 50 wt%, at least 60 wt%, or at least 70 wt%, based on the total weight of the polymeric components of the (final) foam composition. In certain embodiments, the one or more hydroxy-ethylene-butylene copolymers are present in the polymeric component in an amount of up to 100 wt%, up to 90 wt%, or up to 80 wt%, based on the total weight of the polymeric components of the (final) foam composition. These values ​​also characterize the polymeric components prior to foaming when the water of the foamable composition is not included.

[0050] In certain embodiments, the foamed composition is formed from a foamable water-containing composition comprising at least 1 wt%, at least 10 wt%, at least 15 wt%, at least 25 wt%, at least 50 wt%, at least 60 wt%, or at least 70 wt% of a hydroxy-ethylene-butylene copolymer based on the total weight of the (final) foamed composition. In certain embodiments, the foamed composition is formed from a foamable water-containing composition comprising up to 99.5 wt%, up to 95 wt%, up to 90 wt%, up to 80 wt%, up to 70 wt%, or up to 60 wt% of a hydroxy-ethylene-butylene copolymer based on the total weight of the (final) foamed composition.

[0051] When used, the one or more second polymers are present in the polymer component in an amount of up to 99%, up to 90%, up to 80%, up to 75%, up to 60%, up to 50%, up to 40%, or up to 30% by weight, based on the total weight of the polymer component of the (final) foam composition. When used, the one or more second polymers are present in the polymer component in an amount of at least 10%, at least 20%, at least 30%, at least 40%, or at least 50% by weight, based on the total weight of the polymer component of the (final) foam composition.

[0052] In certain embodiments, the polymer component comprises a second polymer selected from the group consisting of butanediol vinyl alcohol polymer or copolymer, starch, vinyl acetate / ethylene copolymer, polyvinyl acetate, polyvinyl alcohol, dextrin-stabilized polyvinyl acetate, vinyl alcohol / vinyl acetate copolymer, vinyl alcohol / vinyl acetate / ethylene copolymer, stabilized polyvinyl acrylate copolymer, vinyl(methyl)acrylic, styrene (meth)acrylic, (meth)acrylic, styrene butyl rubber, natural rubber, styrene block copolymer, polyurethane, and mixtures thereof. One such commercially available polymer is polyvinyl alcohol stabilized vinyl acetate ethylene (VAE) emulsion available under the trade name Dur-O-Set (Celanese, Florence, KY USA). In certain embodiments, the second polymer can be neutral or can contain charged monomers (anionic, cationic, zwitterionic).

[0053] Polymers suitable for making foam compositions are typically obtained from suppliers in pellet or powder form and dissolved or dispersed in water. Alternatively, they can be obtained as aqueous dispersions or emulsions. Typically, such dispersions or emulsions have a solids content of 10% to 70% by weight. Thus, the foam compositions (i.e., final foams) of the present disclosure are prepared from aqueous formulations, referred to herein as "foamable" compositions.

[0054] In certain embodiments, the foamable composition is formed from a foamable aqueous composition that includes at least 20 wt. %, at least 30 wt. %, at least 40 wt. %, or at least 50 wt. % solids (i.e., other than water) based on the total weight of the foamable composition before foaming. In certain embodiments, the foamable composition is formed from a foamable aqueous composition that includes up to 70 wt. %, or up to 60 wt. % solids based on the total weight of the foamable composition before foaming. The solids include the polymer component, and any solid blowing agents (or solid residues remaining after foaming), fillers, and other optional solid additives.

[0055] In certain embodiments, the foamed composition is formed from a foamable water-containing composition that includes a foaming agent, such as expandable microspheres. Although these are not required, as other mechanisms of foaming are possible, as discussed below, when they are used, the expandable microspheres are present in an amount of up to 20% by weight, or up to 15% by weight, based on the total weight of the composition before foaming. In certain embodiments, when they are used, the expandable microspheres are present in an amount of at least 0.5% by weight, based on the total weight of the composition before foaming.

[0056] In certain embodiments, the expandable microspheres are thermally expandable polymeric microspheres, i.e., the expandable microspheres are capable of expanding in size in the presence of heat and / or radiant energy (including, for example, microwave, infrared, radio frequency, and / or ultrasonic energy).

[0057] Expandable microspheres have a particular temperature at which they begin to expand (initial expansion temperature or T0) and a second temperature at which they reach maximum expansion (maximum expansion temperature or T m ) Different grades of microspheres have different onset and maximum expansion temperatures. For example, one particularly useful microsphere has a T0 of 80° C. to 150° C. The temperature at which the microsphere reaches maximum expansion (T) is desirably between 100° C. and 200° C. The specific microspheres and their respective T0 and T m The selection of the temperature is not critical, but the processing temperature may be changed depending on these temperatures. Before the composition is completely dry, these microspheres can move and expand within the composition. However, once the composition is completely dry, the microspheres are substantially fixed in place. The expanded composition typically has a total volume expansion of more than 2000%, preferably more than 2500%, from the wet or partially dried composition.

[0058] In certain embodiments, the expandable microspheres have a polymer shell and a hydrocarbon core (eg, a polyacrylonitrile shell).

[0059] Suitable microspheres include, for example, thermally expandable polymer microspheres, including those having a hydrocarbon core and a polyacrylonitrile shell (e.g., those sold under the trade name "DUALITE") and other similar microspheres (e.g., those sold under the trade name "EXPANCEL", e.g., "EXPANCEL 043 DU 80").

[0060] The expandable microspheres may have any unexpanded size, including from 5 microns to 30 microns in diameter. In the presence of heat, the expandable microspheres of the present invention may be capable of increasing in diameter by 3 to 10 times. When the microspheres in the composition expand, the composition becomes a foamed material. Alternatively, the expandable microspheres may be pre-expanded prior to combination with the polymeric component and allowed to fully expand without the need for further expansion.

[0061] Although expandable microspheres are preferred, other foaming mechanisms can be used if desired. For example, polymer foams can be prepared mechanically (e.g., air dispersion), physically (e.g., by gas injection, bead expansion, expandable microspheres), or chemically (e.g., by using a blowing agent that generates effective gas by thermal decomposition). For example, blowing agents other than expandable microspheres can be used, including physical blowing agents or chemical blowing agents. When used, the one or more blowing agents are present in an amount of up to 20% by weight, or up to 15% by weight, based on the total weight of the composition before foaming. In certain embodiments, when used, the one or more blowing agents are present in an amount of at least 0.5% by weight, based on the total weight of the composition before foaming.

[0062] Physical blowing agents useful for forming the foam composition of the present disclosure can include a wide variety of natural atmospheric substances that are vapors at the temperature and pressure at which the foam is formed. The physical blowing agent can be introduced to the polymeric component as a gas, liquid, or supercritical fluid, preferably as a liquid. The physical blowing agent is usually in a supercritical state at the conditions present during the foaming process. When a physical blowing agent is used, it is preferably soluble in the polymeric component used. The physical blowing agent used depends on the properties desired in the resulting foam article. Other factors considered in selecting a blowing agent are its toxicity, vapor pressure profile, and ease of handling. Flammable blowing agents such as pentane, butane, and other organic materials such as hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) can be used, but non-flammable, non-toxic, non-ozone depleting blowing agents are preferred because they are easier to use and, for example, have fewer environmental and safety concerns. Suitable physical blowing agents include, for example, carbon dioxide, nitrogen, SF6, nitrous oxide, perfluorinated fluids such as C2F6, argon, helium, noble gases such as xenon, air (a blend of nitrogen and oxygen), and blends of these materials, hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs).

[0063] Suitable chemical blowing agents include, for example, sodium bicarbonate and citric acid blends, dinitrosopentamethylenetetramine, p-toluenesulfonyl hydrazide, 4-4'-oxybis(benzenesulfonyl hydrazide, azodicarbonamide (1,1'-azobisformamide), meta-modified azodicarbonide, p-toluenesulfonyl semicarbazide, 5-phenyltetrazole, 5-phenyltetrazole analogs, diisopropylhydrazodicarboxylate, 5-phenyl-4-oxadiazin-2-one, and sodium borohydride. Another exemplary chemical blowing agent includes that available under the tradename HYDROCEROL 40 CB from Avient (Avon Lake, Ohio).

[0064] The foam composition, and the water-containing foamable composition from which it is formed, may also include one or more additional optional additives. Examples of suitable optional additives include tackifiers (e.g., resin esters, terpenes, phenols, and mixtures of aliphatic, aromatic, or aliphatic synthetic hydrocarbon resins with aromatic synthetic hydrocarbon resins), plasticizers (other than physical foaming agents), nucleating agents (e.g., talc, silicone, or TiO2), colorants (e.g., pigments, dyes), reinforcing agents, solid fillers (e.g., pearl starch, physically modified starch, chemically modified starch, glass microspheres, clay, cork, sawdust, sand, inorganic particles (e.g., ceramic or metal), organic particles (e.g., carbon black particles, wood pulp, nanocrystalline cellulose, water-insoluble crosslinked polymer particles such as polystyrene-divinylbenzene), rheology modifiers, toughening agents, and the like. agents), thickening agents (e.g., water soluble cellulose ethers, fumed silica, thermoplastic starch, synthetic polymers or oligomers which can be linear, branched, hyperbranched, dendritic, or star-shaped in structure), flame retardants, preservatives (e.g., biocides, 1,2-benzisothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and 2-methyl-4-isothiazolin-3-one), antioxidants, antifoaming agents, crosslinking agents (which increase the structural integrity of the composition after the microspheres are expanded), waxes (e.g., paraffin wax, beeswax, synthetic polyethylene wax), stabilizers (e.g., UV stabilizers), wetting agents, accelerators, antistatic agents, slip agents, and combinations thereof.

[0065] Although tackifiers can be used, they are typically not used in the foamable / foam compositions of the present disclosure. Although the foam compositions of the present disclosure can function as thermoplastic structural adhesives, especially in forming seal joints (i.e., seams), they are preferably not pressure sensitive adhesives.

[0066] The optional additives may be used in various combinations and amounts sufficient to obtain the desired properties for the foam produced. Typically, one or more such additives are present in an amount of at least 0.05% by weight, based on the total weight of the foamable water-containing composition (before foaming). In certain embodiments, the one or more optional additives are in an amount of up to 15%, up to 10%, or up to 5% by weight, based on the total weight of the foamable water-containing composition (before foaming).

[0067] The foamable compositions of the present disclosure desirably have a viscosity that allows for high speed printing / coating / spraying / spraying / overlaying or similar processes for deposition onto a substrate. Useful ranges of viscosity include 300 to 100,000 cPs at 25° C., desirably 1000 cPs to 70,000 cPs at 25° C., as measured using a rheometer at shear rates of 0.1 to 11 Hz per second according to the Brookfield Viscosity Test in the Examples section.

[0068] A variety of methods of printing, coating, spraying, painting, overlaying, or otherwise applying the foamable water-containing composition to a substrate may be used to form the foamable composition of the present disclosure. In particular, screen printing, rotogravure printing, and random element printing methods may be used as described in the Examples section.

[0069] Following application of the foamable water-containing composition described herein to a substrate, the coated substrate is exposed to conditions that cause foaming of the foamable composition. This preferably involves exposing the coated substrate to an elevated temperature for a time effective to form a foam and adhere the foam to the substrate. In certain embodiments, the temperature is equal to or greater than the melting temperature of the polymeric component of the foamable composition. For polymeric components that include one or more hydroxy-ethylene-butylene copolymers, a temperature of at least 170° C. for at least 1 minute is preferred. If the temperature and / or time of this step is too low, a foam may form, but the foam may not adhere sufficiently to the substrate or may not form a sufficient microstructure to provide cushioning or other desired functionality.

[0070] Coated Substrate The present disclosure provides coated substrates comprising a sheet material having a surface having disposed thereon a foam composition as described herein. Such coated substrates can be used in packaging materials to provide padding and to impart one or more of the following properties to the foam padded material or packaging article: impact protection, cushioning, insulation, compression resistance, water resistance, regenerability, and / or compostability.

[0071] Preferably, the coated substrate is a renewable and / or compostable foam padded material suitable for use in making packaging articles. More specifically, the foam padded material comprises a sheet material 10 having first and second major surfaces (12, 14), the sheet material comprising a renewable material, and a foam composition 16 disposed on the first major surface 12 of the sheet material, the foam composition comprising a polymeric component comprising a water soluble copolymer comprising divalent hydroxyethylene monomer units and divalent dihydroxybutylene monomer units, the foamable composition being in the form of an at least partially water soluble foam.

[0072] The foamed composition may form a continuous or discontinuous coating on the surface of a substrate (e.g., a sheet material), or a combination of the two. In certain embodiments, the foamed composition is arranged in a discontinuous pattern comprising an array of discrete elements. Such discrete elements can be in the form of a wide variety of geometric shapes, for example, squares, rectangles, triangles, spirals, lines, circles, etc.

[0073] In other embodiments, the final foam composition 16 can have a continuous or substantially continuous overall coating 18 on the first major surface 12 of the sheet material 10, and then a discontinuous pattern 20 comprising an array of discrete elements disposed on the continuous coating, as shown in Figures 13A and 13B. As shown in the examples below, utilizing both coating layers can improve the heat sealability of the foam composition because while the foam composition has a continuous coating layer, it also has significant cushioning capabilities due to the discontinuous pattern coating layer. As shown in Figure 12, a rotogravure roll with the appropriate cell pattern can apply both coating layers in a single printing pass. Alternatively, the different coating layers can be applied by two coating stations with different rotogravure rolls.

[0074] In a discontinuous pattern, there are spaces between elements in the array of elements. The pattern is selected to allow for proper expansion of the expandable composition upon deposition onto the substrate surface. Any selected pattern may include one or more variations in spacing for expansion. For example, discrete regions of the composition may be used that are not connected or discontinuous to other discrete regions of the composition, or discrete regions of the expandable composition may be used in combination with connecting bridges between the discrete regions such that they are connected but still provide expansion space. The discrete regions may be of any shape or configuration that serves the purpose of providing protective padding upon expansion. Such patterns may be regular or irregular (i.e., including a random array of elements). Non-limiting examples of such patterns are shown in Figures 1A-1G. The patterns may be configured in a variety of ways to fit the final product and provide the desired padding. For example, the pattern may be a series of linear or non-linear spaced elements of the composition. These elements may be connected in one or more locations, may be arranged in parallel or non-parallel configurations, and may form, for example, recognizable text, images, or logos.

[0075] Each element of the array of discrete elements of the foam composition has a length and a width, typically with at least one dimension in the range of 0.05 inches to 2.0 inches (1.27 to 50.8 mm) and at least one dimension in the range of 0.1 inches to 2.5 inches (2.5 to 63.5 mm).

[0076] The substrate surface area may be 100% covered by the discrete elements of the foam composition (i.e., foam), but typically is less than 100% covered. In certain embodiments, the foam composition covers at least 10%, at least 20%, or at least 30% of the substrate (e.g., sheet material) surface area. In certain embodiments, the foam composition covers up to 100%, up to 90%, up to 80%, up to 70% of the substrate (e.g., sheet material) surface area. The coverage may be higher in certain regions than in other areas. For example, the coverage may be higher in regions on the substrate that form a seal with another substrate (e.g., on the edges of the sheet material that form the walls of an envelope). Alternatively, the coverage may be lower or completely absent in regions on the substrate (e.g., on the portions of the sheet material that form the flaps of an envelope).

[0077] In certain embodiments, the foam composition is disposed on the surface of the substrate (e.g., sheet material) in an amount (i.e., coating weight) of at least 5 grams per square meter (gsm), at least 10 gsm, at least 15 gsm, or at least 20 gsm. In certain embodiments, the foam composition is disposed on the surface of the substrate (e.g., sheet material) in an amount of up to 120 gsm, up to 110 gsm, up to 100 gsm, up to 90 gsm, up to 80 gsm, up to 70 gsm, up to 60 gsm, up to 50 gsm, or up to 40 gsm. This can be determined using the Foam Weight Test described in the Examples section.

[0078] In other embodiments where both a continuous foam composition coating layer and a discrete element discontinuous foam composition coating layer are present, the coating weight range of the continuous foam coating can be 0-50 gsm, 5-30 gsm, or 5-20 gsm. The weight range of the discontinuous discrete foam elements can be 5-100 gsm, 10-80 gsm, or 15-70 gsm. The total coating weight on the substrate is the sum of the individual weight ranges.

[0079] In certain embodiments, the foamed composition (i.e., each element of the array of discrete elements of the foamed composition) disposed on a surface of a substrate (e.g., a sheet material) has a height of at least 0.25 mm, at least 0.5 mm, at least 1.0 mm, at least 2 mm, and often up to 10 mm, or even up to 50 mm.

[0080] The foam composition may be exposed or may be covered (at least partially) or encapsulated by one or more sheet materials (e.g., paper or other cover sheets), such that the foam padding material forms a "sandwich" with the foam composition sandwiched between two sheet materials, which may be the same or different. Such foam padded materials may include, for example, paper / foam / paper or paper / foam / foam / paper structures and may be used to make multi-layer padded mailing articles.

[0081] The renewable and / or compostable padding material can be provided in any size and shape, and is typically provided in roll form that can be easily cut into discrete lengths to form packaging articles, e.g., envelopes.

[0082] Sheet material In certain embodiments, the sheet material of the foam-padded material and the walls of the packaging article comprise a renewable material. In certain embodiments, the recyclable material is a repulpable material such as paper. Preferably, the sheet material of the foam-padded material and the walls of the packaging article contain only repulpable paper and are therefore described as consisting of repulpable paper. The sheet material of the foam-padded material and the walls of the packaging article can be one material or two or more materials, and the materials constituting the first and second walls can be the same or different.

[0083] As used in this context, "paper" refers to a product or fabric in sheet form (which can be foldable and of various thicknesses), woven or nonwoven, made from cellulose (especially cellulose fibers (either natural or artificial)) or which may otherwise be derived from the pulp of plant sources such as wood, corn, grass, rice, etc. Paper includes products made from both traditional and non-traditional papermaking processes, as well as materials of the above types in which other types of fibers, such as reinforcing fibers, are embedded within the sheet. Paper may have a coating on the sheet or on the fibers themselves.

[0084] Any form of paper can be used, but it is preferred that the paper is repulpable (i.e., can be turned into pulp). Paper (or cellulose fibers) are inherently pulpable, but once papers are processed, their recyclability depends on the amount of fiber separated during the repulping process; for example, in the United States there is a voluntary standard that specifies a minimum fiber recovery rate of 80%. This standard was developed by a joint committee of the Fibre Box Association and the American Forest & Paper Association (AF&PA).

[0085] Exemplary paper sheet materials include kraft liner paper, fiberboard, chipboard, corrugated paper, paper medium, corrugated medium, solid bleached board (SBB), solid bleached sulphite board (SBS), solid unbleached board (SLB), white lined chipboard (WLC), kraft paper, kraft board, coated paper, internally sized paper, binder board, or mixtures thereof. Examples of non-traditional products that are "paper" within the context of this disclosure include the material available under the trade name TRINGA from PAPTIC (Espoo, Finland) and the sheet form of the material available under the trade name SULAPAC. Kraft paper is particularly useful for this purpose, although other papers may be used.

[0086] Exemplary sheet materials that can be used have a basis weight sufficient to enable them to withstand weather conditions such as heat, cold, rain, or snow, and other conditions that may be encountered during the packaging and shipping process, as well as to withstand handling that may occur during packaging and shipping, such as dropping, jostling, hitting other materials, etc. Any basis weight suitable for the intended use may be used, and various basis weights may be suitable depending on the needs of the user. Most commonly, basis weight (grams per square meter (g / m2)) is used to measure the surface area of ​​the sheet. 2 or gsm) is at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70 gsm. Most commonly, the basis weight (g / m 2The basis weight (in gsm) is up to 200, up to 150, up to 140, up to 130, up to 120, up to 110, up to 100, up to 75, up to 70, up to 65, up to 60, up to 55, up to 50, up to 45, up to 40, up to 35, up to 30, or up to 25 gsm. Most commonly, the basis weight (in g / m 2 ) is a unit of thickness ranging from 30 to 200 gsm.

[0087] In certain cases, a single sheet of material is folded to create both the first and second walls from the same sheet of material, thereby providing the first and second walls with the same components and made from the same material. This can be particularly advantageous for facilitating assembly or manufacturing of the packaging article. In such cases, one end or edge of the sheet can overlap the opposing end or edge of the sheet to form a tube. The tube can be sealed by attaching the overlapping portion. The resulting tube may be open at both ends. Both of the last two openings can be sealed after an object is placed in the packaging article, or one opening can be sealed, then an object is placed in the packaging article, and then the remaining openings can be sealed. This can be accomplished by methods described herein or known in the art, for example, by use of a bag sealing machine, impulse sealer, heat sealer, etc.

[0088] It is not necessary that the first wall and the second wall are made of the same material sheet. It is also possible to attach two sheets of different materials to make an article with a first wall and a second wall of different materials. This may be advantageous for some intended uses, so the embodiment assembled in this way is also important. It is also possible to attach two sheets of the same material instead of folding one sheet, which is less common, but may be an important mode of implementing the present disclosure for some intended uses of packaging articles.

[0089] The first wall, the second wall, or both, may be comprised of a single layer or sheet of material, or multiple sheets.

[0090] When multiple sheets (i.e., layers) are used for the first wall, the second wall, or both, they can be the same or different layers or sheets. Two, three, four, or even more layers or sheets can be used. In configurations where there are two layers or sheets, one sheet is an inner layer or sheet disposed on the interior of the applicable wall, and the other layer or sheet is an outer layer of a sheet disposed on the exterior of the applicable wall. In configurations where there are three layers or sheets, there is an additional intermediate layer or sheet between the inner and outer layers or sheets.

[0091] One or more of the layers or sheets may be flat layers or sheets. It is also possible that one or more of the layers or sheets may be embossed (before depositing the foam thereon). An embossed layer or sheet may provide some additional cushioning to the contents of the packaged article and may therefore be advantageous in certain applications. Any embossing pattern may be used, but most often a regular or repeating pattern is used. Examples of repeating patterns are diamonds, squares, circles, triangles, hexagons, as well as mixed patterns with different shapes. When multiple layers or sheets are used, any or all of the layers or sheets may be embossed. Most commonly, when two layers or sheets are used, the inner layer or sheet is embossed and the outer layer or sheet is not embossed. When three layers or sheets are used, typically either the middle layer or the inner layer or sheet is embossed and the other layer or sheet is not embossed. However, other configurations are possible. For example, in a three-layer structure, it may be useful to emboss both the inner and middle layers or sheets to provide additional cushioning beyond that provided by only one embossed layer or sheet.

[0092] Any of the layers or sheets may include a coating that is considered to be part of the layer or sheet. Suitable coatings, which may be selected depending on the requirements of the article or the end use, may include at least one of poly(butylene succinate), poly(butylene succinate adipate), silicone, fluorinated polymer, acrylic, acrylate, poly(ethylene succinate), poly(tetramethylene adipate-co-terephthalate), castor wax, or thermoplastic starch, specifically, poly(butylene succinate), poly(butylene succinate adipate), poly(ethylene succinate), castor wax, or poly(tetramethylene adipate-co-terephthalate), more specifically, poly(butylene succinate), castor wax, or both poly(butylene succinate) and castor wax, most specifically, poly(butylene succinate).

[0093] packaging goods Described herein are packaging articles, particularly those designed for transportation, such as mailers, envelopes, bags, and pouches.

[0094] Packaging articles can take a variety of forms. For example, the article can be a pouch, a bag, a box, a mailing container, or an envelope. Still other forms are possible. Regardless of its form, the article can be completely closed, for example, with an object inside the article, or it can have an opening. The article typically has two walls, a first wall and a second wall, each having an inner surface facing the interior of the article and an outer surface facing the exterior of the article. Thus, the inner surface of the first wall ("first inner surface") faces the inner surface of the second wall ("second inner surface").

[0095] As discussed above, the inner surface of the wall, which may be the coated surface, is the surface of the sheet material that includes the foam composition disposed thereon. The foam composition may be exposed to the interior of the packaging article, in which case no additional sheets or layers are disposed on top of the foam composition. Alternatively, one or more additional layers of sheet material may be disposed on top of the foam composition in the form of one or more cover sheets. In those cases, the packaging article has a structure with the foam composition sandwiched between two sheets or layers of material. The cover sheet may comprise the same or different material as the material that constitutes the wall. Such a wall may comprise one layer of foam-coated sheet material plus a cover sheet, or two layers of foam-coated sheet material, thereby forming, for example, a paper / foam / paper or paper / foam / foam / paper structure. Examples of such multi-layer padded mailing articles are shown, for example, in Figures 11A-C. Such cover sheets may reduce friction experienced by items inserted into the padded mailing article.

[0096] The two walls are typically manufactured from a sheet of material, which may be a single layer of material or multiple layers of material. Each of the walls may be manufactured from a different sheet, in which case the two walls may be made from the same or different materials. More commonly, the first and second walls are manufactured from the same sheet of material, which is folded to produce two separate walls. In these cases, the first and second walls may be made of the same material.

[0097] The first and second walls are attached along at least one edge of the packaging article. Depending on the configuration and shape of the article, they can be attached along two, three, four, or even more edges. The first and second walls can be directly attached so as to be sealed together, or can be indirectly attached by intermediate structures such as gussets, welding, or the like. The packaging article can also include an opening where the first and second walls are not attached.

[0098] The packaging article can include an opening where the first and second walls are not attached, however, an opening is not required as it is also possible to form the packaging article around an object located therein, thereby eliminating the need to manufacture an article with an opening and subsequently close the opening.

[0099] The packaging article includes a foam composition disposed on at least a portion of each of the first and second inner surfaces. The foam composition may form a continuous or discontinuous coating, or a combination of the two coatings, on each of the first and second surfaces. In certain embodiments, the foam composition is disposed in a discontinuous pattern comprising an array of discrete elements. Such discrete elements can be in the form of a wide variety of geometric shapes, for example, squares, rectangles, triangles, spirals, lines, circles, etc. The spacing, size, density, etc. of the foam composition disposed on the inner surface of the packaging article can be the same as described herein for the foam padded material.

[0100] When used, the one or more cover sheets placed on the foam structure can be made of any suitable sheet material or layer. Most commonly, the cover sheet is made of a paper or nonwoven sheet or layer. When paper is used, the paper can be any type of paper depending on the intended use, such as kraft paper, bond paper, crepe paper, etc. When nonwoven is used, it can be any sheet nonwoven, such as one or more polymers or copolymers of lactic acid, lactide, glycolic acid, glycolide, caprolactone, etc. The one or more cover sheets can be coated on one or both sides, for example, with a heat-sealable coating that can include, for example, at least one of poly(butylene succinate), poly(butylene succinate adipate), silicone, fluorinated polymer, acrylic, acrylate, poly(ethylene succinate), poly(tetramethylene adipate-co-terephthalate), castor wax, or thermoplastic starch, specifically, poly(butylene succinate), poly(butylene succinate adipate), poly(ethylene succinate), castor wax, or poly(tetramethylene adipate-co-terephthalate), more specifically, poly(butylene succinate), castor wax, or both poly(butylene succinate) and castor wax, most specifically poly(butylene succinate).

[0101] When used, one or more cover sheets can be secured in place by being secured to all or a portion of the foam composition, or, if not all of the interior surface of the wall is covered by the foam composition, by being secured to one or more portions of the interior surface of the wall that do not contact the foam composition. This can be accomplished by lamination, heat sealing, adhesives, etc., or, if the cover sheet is secured to the foam, by using the foam composition itself as the adhesive, which can be accomplished by contacting the cover sheet with the foam composition while it is not fully cured.

[0102] One or more cover sheets may be used. When cover sheets are used, most commonly the inner surfaces of both walls are covered by the cover sheet. However, this is not required. It should be understood that the use of a cover sheet is optional.

[0103] The packaging articles of the present disclosure also include a seal joint at one or more edges of the first and second walls, In most cases, the seal joint includes or is formed from a foam composition that attaches the first wall to the second wall.

[0104] In making the packaging article, the sheets can be joined together in any suitable manner to form a seal joint at one or more edges of the sheet material (e.g., forming the first and second walls of the packaging article). Preferably, the seal joint can be formed using a foaming composition to attach the first wall to the second wall. Preferably, the foaming composition described herein can be a heat-sealable composition, in which case the sheets can be joined together by a heat sealing process, induction welding, ultrasonic welding, or impulse sealing. A patterned calendar roll or pressure roll can also be used to bond adjacent layers. Alternatively, the foaming composition can be a watertight composition, thereby forming a seal joint upon application of water.

[0105] FIG. 2 shows an exemplary packaged article structure in which the two edges of the first and second walls are attached. In FIG. 2, the article 100 is configured as a bag. The first and second edges 110, 112 are directly attached, joining the first wall 130 with the second wall 140. Only the outer surface 131 of the first wall 130 and the inner surface 142 of the second wall 140 are visible in this view. The opening 150 exists when the first and second walls 130, 140 are not attached. In this case, the bottom 120 is defined by the folds of the sheet material that makes up the article 100.

[0106] 3 shows an alternative structure in which only one edge of the first and second walls is attached, where the exemplary article 200 is also configured as a bag. The single edge 211 attaches to most of the first and second walls 230, 240, leaving them unattached at the opening 250.

[0107] FIG. 4 shows the structure of an exemplary packaging article 300 in which edges 311, 312 are in the form of gussets that attach to first and second walls 330, 340 while leaving an opening 350 unattached.

[0108] Figures 5 and 6 show another exemplary structure of a packaging article 400, which contains a flap 460 and is foldable between an open position, shown in Figure 5, and a closed position, shown in Figure 6. In the open position, the opening 450 is uncovered, while in the closed position, the opening 450 is covered by the flap 460.

[0109] Adhesive part In some embodiments, one or more adhesive portions may be provided. The adhesive portion is not considered to be part of the wall. Typically, when used, the adhesive portion is near the opening of the packaging article and can be used to close the article. When a flap is used, the one or more adhesive portions are often on the flap or on a portion of the outer surface that can be reached by the flap when it is folded into a closed position, thereby allowing the flap to be adhered to the closed position. Often, two adhesive portions are provided.

[0110] The adhesive portion or portions are typically in the form of a strip extending generally parallel to the opening of the packaging article, although this is not required. It is also possible for the adhesive portion or portions to be coated over one or more larger sections or portions of the article, such as, for example, a section or portion of one or more walls or flaps (if flaps are used).

[0111] The adhesive part or parts can be any suitable adhesive depending on the desired application, specifically, renewable, compostable, or recyclable, and most commonly recyclable. In this context, the term "recyclable" refers to materials or compounds that are not themselves renewable, but are easily separated from renewable materials during the recycling process, more specifically, during repulping. Thus, packaging articles can have components such as adhesives that are not themselves renewable, and still be renewable if the non-recyclable components are recyclable.

[0112] In certain cases, one or more adhesive parts are composed of renewable and / or compostable adhesives. One or more adhesive parts can be water-activated adhesives, heat-sealable adhesives, hot melt adhesives, or pressure-sensitive adhesives. Most specifically, pressure-sensitive adhesives are used. Examples of suitable adhesives include copolymers of 2-octyl acrylate and acrylic acid; copolymers of sugar-modified acrylates; blends of poly(lactic acid), polycaprolactone, and resins; blends of poly(hydroxyalkanoates) and resins; protein adhesives; natural rubber adhesives; synthetic rubber adhesives; and polyamides containing dimer acids.

[0113] When a heat sealable adhesive is used, it can be any heat sealable adhesive or hot melt adhesive. Most commonly, the heat sealable adhesive is one that can be sealed with medium or low heat by using an impulse sealer or a heat sealer, such as a handheld heat sealer. Many handheld heat sealers are commercially available for both home and commercial use, such as the Mini Bag Sealer and the iTouchless Handheld Heat Bag Sealer from EEX Co., Ltd. (available from Amazon, USA). Examples of heat sealable adhesives that can be used include poly(butylene succinate), poly(butylene succinate adipate), silicone, fluorinated polymer, acrylic, acrylate, poly(ethylene succinate), poly(tetramethylene adipate-co-terephthalate), castor wax, or thermoplastic starch, specifically at least one of poly(butylene succinate), poly(butylene succinate adipate), poly(ethylene succinate), castor wax, or poly(tetramethylene adipate-co-terephthalate), more specifically poly(butylene succinate), castor wax, or both poly(butylene succinate) and castor wax. Most specifically, poly(butylene succinate) (sometimes called PBS) is used.

[0114] One or more release liners can be placed on any or all of the one or more adhesive portions. The release liners are advantageously compostable and / or recyclable, but this is not essential, since the release liners can be disposed of separately from the packaging article after use and do not need to be placed together with the packaging article in a composting and / or recycling environment. Thus, when the packaging article described herein has one or more release liners, the packaging article can be compostable and / or recyclable even if any or all of the release liners are not compostable and / or recyclable.

[0115] 7A shows an exemplary packaging article 500 having an adhesive portion 501. In this example, the packaging article 500 is formed as a bag, and the adhesive portion 501 is placed near the top of the opening 550 to close the opening 550 if necessary.

[0116] 7B shows an exemplary packaging article 600 having two adhesive portions 601 and 602. In this example, the packaging article 600 is formed as a pouch, and the adhesive portions 501 and 602 are disposed on a flap 660 to close an opening 650.

[0117] 8A and 8B are schematic diagrams of an exemplary packaging article, specifically, an envelope 800 having an uncoated flap 802 (i.e., a portion of the wall material forming the flap of the envelope that does not have foam composition 16 disposed thereon) having an adhesive strip 804 disposed thereon to seal the flap when in a closed position.

[0118] When an article has one or more cover sheets, one or more adhesive portions can be present on the cover sheets. For example, when a heat-sealable coating such as poly(butylene succinate) is used as a coating on some or all of the cover sheets, the heat-sealable coating can function as an adhesive portion.

[0119] Easy-opening mechanism The features or characteristics may be present to facilitate easy opening of the packaged article after it has been sealed. Examples include perforations, scoring, zip tops, or embedded drawstrings or wires. If an opening or flap is present, one or more of these features may be present near the opening or flap to facilitate opening of the packaged article near the opening or flap, or may be present on different parts of the packaged article. These features, if used, are not required to have a specific configuration, most commonly in a straight line parallel to at least one edge of the packaged article, and other shapes or layouts may be used depending on the intended use of the packaged article.

[0120] Method of production and assembly Assembly of the packaging articles described herein can be accomplished by any suitable method.

[0121] One method of assembling the packaging article involves folding one or more layers or sheets, which are joined together when multiple layers or sheets are used to form a first wall and a second wall. When the packaging article is a bag, they can be folded in half. When the packaging article is a pouch or envelope, they can be folded so that there is a flap on the first wall that overhangs the edge of the second wall. The edges can then be attached by heat sealing, ultrasonic welding, impulse sealing, or the like to form the packaging article. The procedure is similar when the first and second walls are made of different materials, as long as one wall has a foam composition disposed therein, in which case all edges, in addition to the opening, can be sealed to form the final article.

[0122] An assembly can be formed by placing an object within any of the packaging articles described herein. The packaging article can then be closed, for example, by folding the flaps to a closed position and attaching the flaps to an exterior surface with at least one of the one or more adhesive portions.

[0123] The assembly and the packaging article can be formed together. For example, an object can be placed on the layer or sheet on which the article or assembly is formed. The article or assembly can then be folded around the object, and the edges can be completely sealed around the object. An article or assembly can be obtained in which the object is inside the packaging article or assembly, and the edges are sealed so that the object cannot fall out unless one or more seals are broken at the edge, or one or more of the layers or sheets are punctured, cut, torn, etc., to create an opening.

[0124] Reseal When one or more adhesive portions are used on the flaps, it is possible to reseal an opened packaged article. For example, an assembly can be formed as discussed above, and then the packaged article can be opened, for example, by tearing the flap of the packaged article at the perforated seal adhesive portion or by tearing the seal of the cover sheet. At this point, the adhesive portion can be utilized to reseal the packaged article. For example, this procedure can be followed when an item shipped in the packaged article is to be returned to the sender in the same packaged article. EXAMPLES

[0125] The following illustrative examples may aid in understanding the present disclosure. However, the present disclosure is not necessarily limited to these examples. There may be disclosed embodiments and concepts that are not specifically illustrated. Unless otherwise noted, all parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight, and all materials used in the examples were obtained or were available from general suppliers, such as, for example, Georgia-Pacific, Atlanta, GA, US. [Table 1]

[0126] Test Method According to the supplier's literature, OKS-8074P G-polymer has a melting temperature of 185°C and a melt flow index (MFI) of 2.0-4.0 grams (g) / 10 minutes (min) measured at 210°C with a load of 2160 g using a melt index measuring device.

[0127] Test Method Brookfield Viscosity: The viscosity of the aqueous polymer dispersions was measured using a Brookfield DV-E Viscometer using spindle #7 operating at 6 revolutions per minute (rpm).

[0128] Foam Weight: Foam weight was measured using TAPPI T 410 OM-19 "Basis Weight (Weight per Unit Area) of Paper and Paperboard." A 10 centimeter (10 cm) by 10 cm (4 in. by 4 in.) square was cut from each foam sample, weighed, and the total basis weight in gsm (grams per square meter) was calculated. To determine the coating weight of the foam only, the basis weight of the substrate was subtracted from the total basis weight.

[0129] Abrasion resistance: Testing was performed using a Model 5750 Linear Abraser (Taber Industries, North Tonawanda, NY, USA) with a flat, smooth stainless steel attachment. The instrument has a free-floating horizontal arm that moves back and forth in a linear motion, and a vertical splined shaft is attached to the horizontal arm, allowing a load to be applied to the shaft. For each experiment, the specimens were cut into strips of approximately 3.81 cm x 10 cm (1.5 in x 4 in). The specimen was fixed to the bottom of the splined shaft so that the stainless steel attachment was in contact with the side of the specimen containing the patterned foam element. Testing was performed with three weight discs attached to the shaft, which represented a total weight of 1100 g applied from the top to the specimen. Each specimen is subjected to 30 cycles of abrasion at a speed of 1 cycle / second for the arm movement of the horizontal abrasion tester. Fresh samples were used for each abrasion experiment and the weight of the sample as well as the weight of the uncoated paper substrate piece were measured before and after the abrasion experiment to calculate the % loss as follows:

number

[0130] Compressive strength and energy absorption and loss: Quasi-static compression testing was completed using an MTS Alliance Load Frame (available from MTS, Eden Prairie, MN, USA). The foamed samples were cut into five specimens, each approximately 2 in x 2 in. The original specimen thickness was measured by preloading the specimen to 10 N. The specimen was compressed axially between two forty millimeter (40 mm) parallel plates at a rate of 1 mm / min until a 50% compressive strain (based on the original specimen thickness) was reached, and then the plates were returned to the original position (0% compressive strain) at a rate of 1 mm / min. The displacement and force were recorded and used to construct a compressive strain (%) vs. compressive stress curve for both the compression and return phases of the test. The absorbed energy was calculated from the area under the first stress-strain curve, and the energy loss was calculated as the difference in the areas under the first and second stress-strain curves. The compressive strength was taken as the compressive stress at 50% compression.

[0131] Water solubility: The samples were subjected to a water solubility test to quantify the percentage of recoverable content. The samples were cut into two test pieces, each approximately 5.1 cm x 5.1 cm (2 inches x 2 inches), and the weight of each test piece was measured and recorded. The test piece of each sample was then placed in a covered glass jar containing 500 g of deionized (DI) water and heated and agitated in a heated shaker water bath (Aqua Pro Linear Shaker Bath available from Grant Instruments, Beaver Falls, PA, USA) operating at 55.5°C (130°F) and 100 strokes per minute. The samples were monitored for up to 6 hours, recording the time that had elapsed until the printed features were visibly peeled off the paper substrate. After the heat soak, the glass jar was removed from the shaker and the paper substrate was removed with tweezers and allowed to air dry. The contents of the glass jar were drained and filtered through a stainless steel wire cloth with 0.5 mm (0.02 in) opening and 57% open area (McMaster-Carr, Elmhurst, IL, USA) to remove excess water, then dried in an oven at 70° C. for 30 minutes (min). The dried remaining contents were then weighed and the % recoverable contents from water dissolution was calculated as follows:

number

[0132] Seam Strength: Seam strength of sealed foam-padded mailing envelopes was measured using the procedure outlined in ASTM F88 / F88M, “Standard Test Method for Seal Strength of Flexible Barrier Materials.” Specimens 2.5 cm (1 in) wide were cut perpendicular to the seam from the sealed mailing envelopes with at least 5.1 cm (2 in) of material on either side of the seam. Prior to testing, specimens were conditioned overnight in a temperature and humidity controlled room at 22.8 ± 1.1 °C (73.1 ± 2 °F) and 50 ± 2% relative humidity. Specimens were loaded into a constant rate of extension tensile testing machine (MTS ALLIANCE RT / 50 TESTING MACHINE, Eden Prairie, MN, USA) with a 1000 N load cell with an initial jaw separation of 3.8 cm (1.5 in). The samples were pulled until the seam separated using an extension rate of 25 cm / min (10 in / min) and the average peak load and total energy of six specimens per sample were recorded. The seam width was measured and the seam strength was calculated by dividing the peak load by the seam width.

[0133] Sample preparation procedure Concentration / foaming temperature test Five hundred grams (500 g) of G-polymer was dissolved in 1167 g of DI water under mechanical agitation to prepare an aqueous dispersion having a solids content of 30% by weight. Aliquots of this dispersion were further diluted to obtain dispersions having solids contents of 5%, 10%, 15%, 20%, and 25% by weight, respectively. Five grams (5 g) of expandable microspheres (043 DU 80) were added to 100 grams of each of these polymer dispersions, followed by mixing for 10 minutes (min) such that the concentration of expandable microspheres in the dispersion ranged from 2% to 8% by weight. Similarly, METHOCEL K4M thickener was added to each dispersion and mixed, such that the final concentration of thickener in the dispersion ranged from 1% to 6% by weight. After mixing, the 20 wt%, 25 wt%, and 30 wt% copolymer dispersions had Brookfield viscosity values ​​ranging from 1000 to 70,000 centipoise (cP) at 25°C.

[0134] Each of the dispersions was deposited onto 55 pound Kraft paper using a 12 inch (in) x 12 in) hand stencil as shown in FIG. 9A and then placed in an oven at either 105° C. or 170° C. The samples were evaluated for two attributes: whether a foam was obtained, and whether the resulting foam remained on the substrate or exhibited shedding or flaking when rubbed with a hand. The results are summarized in Table 2. All formulations foamed well at 105° C., but the foam easily flaked off when rubbed with a hand. All formulations foamed well at 170° C., but foamable compositions with solids of 20 wt % or greater did not exhibit shedding or flaking under hand abrasion. [Table 2]

[0135] Preparation of the Foamable Composition The formulations of the foamable compositions are summarized in Table 3A. Five hundred grams (500 g) of G-polymer was weighed and dissolved in 1500 g of DI water under mechanical agitation to prepare an aqueous dispersion with a solids content of 25% by weight. For formulations 2 and 4, 100 g of DUR-O-SET E230 emulsion was added to 100 g of 25% G-polymer dispersion and mixed. An appropriate amount of expandable microspheres was then added to 200 grams of the polymer dispersion and mixed for 10 minutes. An appropriate amount of thickener was added and mixed for an additional 10 minutes. To prepare comparative formulation 5, expandable microspheres and thickener were added to DUR-O-SET C-335 emulsion and mixed for 10 minutes. Table 3B summarizes the composition of the materials after foaming and drying using the following procedure. [Table 3] [Table 4]

[0136] Screen Printing and Foaming - Examples 1, 2, and Comparative Example CE5 Formulations 1 and 2 were used to prepare the padded foam sheets of Examples 1 and 2, respectively, and Comparative Formulation 5 was used to prepare Comparative Example CE5. The foamable formulations were each screen printed onto a sheet of 55 lb. Kraft paper using a hand stencil 90 shown in FIG. 9A. The template had a 10% open area percentage, with the bars each measuring 4 mm long by 1.5 mm wide by 1 mm thick, with each cell spaced 15 mm apart. The mixture was poured onto one edge of the template, and then a squeegee was used to pull the mixture across the stencil, filling the voids and transferring it to the substrate. The stencil was then removed and the coated paper was placed in a 170° C. convection oven for 4 minutes to form the foam composition 16 shown in FIG. 9B.

[0137] Random Pattern Printing and Foaming - Examples 3A, 3B, 4A, and 4B Formulation 3 was used to prepare padded foam sheet examples 3A and 3B, and formulation 4 was used to prepare padded foam sheet examples 4A and 4B. The foamable formulations were deposited onto a roll of 55 pound kraft paper using the process shown in Figures 10A and 10B. The kraft paper substrate reel was placed on the unwind station shown in Figure 10A. The paper was fed to the rotogravure station and the drive nip was closed. An air motor was used to regulate the web speed of the paper substrate to about 2.4 meters / minute (m / min, 8 feet / min) as it was fed to the die coating station.

[0138] A schematic of the die coating station 100 used to coat Examples 3A and 4A is shown in FIG. 10B. A standard extrusion die similar to a PREMIERE fixed lip slot die (available from Nordson Corp., Westlake, OH, USA) was used to periodically deposit adhesive onto the kraft paper substrate 12 as it moved through the coating station. The height of the extrusion die slot was controlled with 0.51 mm (0.02 in) thick shims. The width of the die slot was 28 cm (11 in). The length of both the upstream and downstream die lips was 0.51 mm (0.02 in). The upstream die lip was flush with the downstream die lip. The aqueous coating formulation was placed into a 0.95 liter (32 oz) plastic SEMCO dispensing cartridge (available from Fishman Corp., Hopkinton, MA, USA). The filled cartridge was then pumped into a SEMCO Model 550 sealant gun (Fishman The web was placed into a dispensing system similar to that available from Eppendorf Automotive Corp., Hopkinton, MA, USA. To initiate cyclic coating, a drive nip was engaged on the coating line to move the web. The die was positioned close to the moving substrate with a gap of 0.13 mm (0.005 in). The die was aligned so that the center of the die slot was at the same height as the center of the rotation axis of the backup roll, as shown in FIG. 10B. The die slot was held horizontal as indicated by the bubble level. The dispensing system was engaged and operated to deliver an adhesive flow rate of 20 cc / min. The gap between the downstream die lip and the substrate during adhesive deposition was increased from 0.127 mm (0.005 in) to about 0.762 mm (0.03 in) to transition from continuous film coating to controlled random deposition of coating 17 (before drying and expansion). The die gap was further increased to about 1.5 mm (0.06 in) as the adhesive flow rate increased to 40 cubic centimeters per minute (cc / min).

[0139] For Examples 3B and 4B, a sheet of 10 mil thick polyester sheet was cut into shims with 0.5 in. wide teeth spaced 0.5 in. apart. The shims were placed in the die slot during coating to produce a stripe pattern with each stripe consisting of randomly placed dots.

[0140] The coated paper exited the die coating station and was fed into a single-zone oven (available from Drying Systems Company, Morton Grove, IL, USA) set at 182°C (360°F). The coated substrate was passed through the 2.74 m (9 ft) length of the oven supported on an idler roll. A rubber covered, pneumatically driven pull roll moved the substrate from the oven and delivered it to a winder which wound the dry, coated substrate onto a reel.

[0141] Constructing a foam-padded envelope Table 4 summarizes the materials and construction procedures used to prepare exemplary foam-padded mailing containers. In Procedure A, sheets of foam-coated kraft paper were cut to dimensions of approximately 30.5 cm (12 in) wide by 61 cm (24 in). Each sheet was folded foam-coated side inward and heat sealed along the edges using a Model iS2-20-20" Impulse Sealer (available from IMPAK Corporation, Sebastian, FL, USA) set at 204°C (400°F) at 345 kilopascals (kPa, 50 psi) of pressure for 0.5 seconds to form flat sealed mailing containers approximately 30.5 cm (12 in) wide by 30.5 cm (12 in) long with an opening at one end.

[0142] In Procedure B, a sheet of foam-padded kraft paper was prepared as above, except that a 6.4 cm (2.5 in) wide section along the edge was left uncoated (i.e., had no foam padding). The sheet was cut to initial dimensions of approximately 37 cm (14.5 in) wide by 61 cm (24 in) long, with the uncoated section extending along the long edge. Half of the uncoated portion was removed and the sheet was folded with the foam-coated side facing inwards to form an overlapping area approximately 30.5 cm (12 in) wide by 30.5 cm (12 in) long, with the protruding flap being approximately 6.4 cm (2.5 in) long. An uncoated (i.e., as received) sheet of Kraft paper approximately 29.2 cm (11.5 in) wide by 29.2 cm (11.5 in) long was inserted between the walls of the folded structure to serve as a smooth cover sheet along one wall of the padded mailing article (as shown in FIG. 11A). The article was heat sealed along the side edges and along the edges of the flaps using the procedure described for Procedure A. A strip of 9925XL tape was then applied to the flaps parallel to the edges and approximately 0.95 cm (0.38 in) from the edges, leaving the release liner on the adhesive strip.

[0143] Procedure C was similar to Procedure B, except that the paper cover sheet did not cover the entire wall of the mailer (as shown in FIG. 11B). Prior to heat sealing, an uncoated sheet approximately 29.2 cm (11.5 in) wide by 7.6 cm (3 in) long was inserted between the walls and aligned with the top edge of the flap. The article was heat sealed along the side edges and along the edge of the flap using the procedure described for Procedure A. A strip of 9925XL tape was then applied to the flap parallel to the edge and approximately 0.95 cm (0.38 in) from the edge, leaving the release liner on the adhesive strip.

[0144] For Procedure D, a sheet of foam-padded kraft paper was prepared as described for Procedure B, with the edges uncoated (as shown in FIG. 11C). The sheet was cut to initial dimensions of approximately 37 cm (14.5 in) wide by 61 cm (24 in) long, with the uncoated portion extending along the long edge. Half of the uncoated portion was removed, and an uncoated sheet of kraft paper approximately 6.4 cm (2.5 in) wide by 58 cm (23 in) long was placed lengthwise on top, aligned with the cut-out portion. The uncoated paper was heat sealed to the foam-padded paper along the long edge (using the procedure described for Procedure A), and the sheet was folded with the foam-coated side facing inwards to form an overlapping area approximately 30.5 cm (12 in) wide by 30.5 cm (12 in) long, with a protruding flap approximately 6.4 cm (2.5 in) long. The uncoated paper formed a short cover sheet around the inside perimeter of the opening of the mailing article. The article was heat sealed along the edges using the procedure described for Procedure A. A strip of 9925XL tape was then applied to the flap parallel to the edge and approximately 0.95 cm (0.38 in) from the edge, leaving the release liner on the adhesive strip.

[0145] Procedure E was similar to Procedure B, except that the cover sheet was an additional sheet of foam-padded paper instead of uncoated paper. Prior to heat sealing, an additional sheet of foam-padded paper approximately 29.2 cm (11.5 in) wide by 29.2 cm (11.5 in) long was inserted between the walls of the folded structure with the foam side facing the long side of the fold and the insert aligned with the top edge of the flap. The article was heat sealed along the side edges and along the edge of the flap using the procedure described for Procedure A. A strip of 9925XL tape was then applied to the flap parallel to the edge and approximately 0.95 cm (0.38 in) from the edge, leaving the release liner on the adhesive strip. [Table 5]

[0146] result The coating weights and overall sample thicknesses of the foam padded materials are provided in Table 5. To calculate the coating weight, the basis weight of the kraft paper was assumed to be 81 gsm. The combined thickness of the foam and paper was measured using a simple caliper, with the uncoated kraft paper being 0.14 mm (5.5 mils) thick. [Table 6]

[0147] Compression test results (specifically, compression strength, stored energy, and energy loss) were used to evaluate the impact and cushioning performance of the foam padded material of the present invention. Table 6 compares the compression test performance parameters of the padded foam coated sheet of Example 4 with two commercially available padded mailers. Comparative Example CE2 was a padded mailer with foam between two layers of paper (ECO MAILER™ available from Technical Machinery Solutions (TMS), Elk Grove Village, IL USA), and Comparative Example CE3 was a paper covered plastic bubble mailer (SCOTCH 7972-100-CS, 3M Company, St. Paul, MN, USA). Examples 1-4B, each with only a single paper layer, showed comparable compression strength to CE2, which contained a double layer structure. Examples 1-4B showed higher energy loss compared to both CE2 and CE3, which is interpreted as meaning that Example 4 can absorb impact forces better than both comparative materials. Examples 1-4B also show a higher percentage of energy lost relative to absorbed energy than both CE2 and CE3, which is interpreted as meaning that Example 4 is better able to dissipate impact forces than both comparative materials. [Table 7]

[0148] The results of the abrasion tests are summarized in Table 7 and were used to evaluate the durability of the foam-coated samples. Examples 1 and 4A had significantly less foam weight loss after abrasion. In addition, it was observed that after abrasion, the printed features on Examples 1 and 4A were significantly flattened, but the features remained primarily attached to the paper substrate. In contrast, the printed features on CE1 appeared brittle and the top layer was removed by abrasion.

[0149] The results of the water solubility test are also shown in Table 7. Both Examples 3A and 4A showed a higher amount of recovered content than CE1, suggesting that the foam compositions of the present invention are more water soluble than CE1, which was prepared using a homopolymer rather than a copolymer. [Table 8]

[0150] The results of seam strength testing for the padded foam packaging articles of Examples 5A, 6A, and 7A, and Comparative Examples CE2 and CE3, are summarized in Table 8. Examples 5A, 6A, and 7A were heat sealed without the use of an additional adhesive. The foam itself acted as the adhesive, and showed comparable seam strength to CE2, which contained a seam adhesive. [Table 9]

[0151] Foamable composition, rotogravure printing of Examples 6G to 10G The formulation of Example 1G was used to prepare the padded foam sheet of Example 6G. A roll of Kraft paper substrate was placed on the unwinder as shown. The paper was fed to the rotogravure printing station and the drive nip was closed. An air motor was used to regulate the web speed of the paper substrate to about 2.4 meters per minute (m / min, 8 ft / min) as it was fed to the rotogravure station. The coated paper was passed through an oven set at 360°F (182°C).

[0152] Using a process using a rotogravure printing station with a gravure roll sleeve having dimensions of 7.62 cm inner diameter, 10.3 cm outer diameter by 35.5 cm length, 3D printed using a Stratasys F370 FDM printer using ABS filament with a layer height of 0.007", the foamable composition was deposited onto a roll of 55 lb kraft paper and placed on a 7.6 cm metal shaft to form a gravure roll 180 with 2 mm deep cells aligned around the diameter as shown in FIG. 14. The land area between the cells of the 3D printed sleeve was 1.03 cm. The pattern of the roll is listed in Table 9 as Gravure Pattern 2.

[0153] An unexpected benefit of 3D printing to create the gravure roll was that the 3D printing process left ridges and valleys in the circumferential direction. Metal machined gravure rolls are usually perfectly smooth in the land areas between the large circular holes that form the discrete elements. Thus, in addition to printing the foamable composition of the discrete foam elements, the surface of the substrate was also printed with closely spaced lines that formed and created a continuous foam coating layer on the substrate. The continuous foam layer is believed to significantly increase the seam strength of heat sealed packaging articles such as mailers and envelopes, enhancing the durability of the discrete foam elements by more firmly anchoring them to the substrate.

[0154] The resulting foam coating using the gravure roll of Figure 14 on a substrate is shown in Figures 13A and 13B. As seen in Figure 13B, the printed lines from the 3D printed gravure roll appear as faint lines in the continuous coating layer between the discrete elements. The continuous coating layer ends near the edge of the substrate 10 leaving uncoated areas 19, in this case where only the kraft paper surface is present. The foamable composition in this embodiment was dyed to match the color of the kraft paper for more visual appeal.

[0155] In one embodiment, the total coating weight added was 38.1 gsm. The discrete elements weighed 18 gsm and the continuous coating weight was 20 gsm. In a second embodiment, the total coating weight was 66.1 gsm, the discrete elements had a coating weight of 39.4 gsm, and the continuous coating weight area was 26.8 gsm. The continuous foam coating can range from 0 to 50 gsm, 5 to 30 gsm, or 5 to 20 gsm. The discontinuous discrete foam elements can range from 5 to 100 gsm, 10 to 80 gsm, or 15 to 70 gsm. The total coating weight is the sum of the previous individual ranges.

[0156] Referring to FIG. 12, a gravure roll having both discrete circular elements 185 and a plurality of microgrooves 187 is used to illustrate the concept of printing a foamable composition onto a substrate to form a continuous foam coating. The discrete elements are formed by large circular apertures arranged in a parallelogram pattern that place the foamed discrete elements in a row of lines angled relative to the edge of the substrate. A continuous coating layer is laid down by circumferential grooves in the land areas of the roll between the apertures. This can be accomplished by 3D printing closely spaced circumferential lines or filaments on the roll surface. Since the composition foams after application, laying down the foamable composition in discrete lines forms a substantially continuous coating on the substrate as the composition foams. Rather than 3D printing a gravure roll, machined rolls with similar features can also be constructed.

[0157] The gravure roll coating technique allows for a continuous foam coating between the discrete foam elements. This continuous coating provides a continuous heat sealable layer over the entire surface. This continuous coating substantially increases the seam seal strength when heat sealing. The resulting seam seal strengths of the gravure roll coated samples in Table 14 range from 3.5 kgf / cm to 4.5 kgf / cm. For various embodiments, the seam seal strength is at least 0.5 kgf / cm, 1.0 kgf / cm, or 1.5 kgf / cm.

[0158] A dye was added to the foamable composition to match the color of the foam to the color of the Kraft paper on which it was coated. The dye coating created a good color match between the discrete elements, and the continuous coating layer and the Kraft paper, resulting in a visually appealing article. In some embodiments, the concentration of the dye ranges from 0.01% to 5.0% by weight. [Table 10] [Table 11] [Table 12] [Table 13] [Table 14] [Table 15]

[0159] Comparing the results of Table 8 with Table 14, it is shown that the substrate having both a continuous or substantially continuous foam coating layer combined with a discontinuous foam coating layer of discrete elements significantly improved the heat sealed seam strength of the packaged article. In particular, the seam strength increased from a range of 1.25-1.32 lbf / in to a range of 1.66-1.86 lbf / in, which is of significant benefit when forming heat sealed padded mailers utilizing a foamable composition at the seam to seal the edges. The padded substrate also had good cushioning properties when used for packaging because it had sufficient pattern for the discrete elements as in the previous examples.

[0160] The foam-coated substrate having a continuous foam layer and discrete foam elements can be formed into any of the packaging articles shown in Figures 2, 3, 4, 5, 6, or 7 and the above discussion of how to make them. It is particularly suitable for forming envelopes having heat-sealed seams and sealing flaps, such as an envelope having three heat-sealed seams forming an inner pouch and a sealing flap closure as shown in Figures 11A-11C. These packages are often called mailers and are used to transport products from online retailers to customers.

[0161] Rotogravure printing of foamable composition, medium air bubbles The following examples show the rotogravure printing of a foamable composition to form a plurality of foam cells 170 having a foamed outer shell 171 and a hollow interior 173 filled with air, as best seen in Figure 17. At the top edge of the substrate 10 in Figure 17, the foam cells have been cut open to expose the hollow interior center 173 and the foamed outer shell 171 surrounding the hollow center. Tables 15 and 16 list the rotogravure roll patterns tested and additional materials used in the foamable composition. Tables 17-22 show the wet and dry weights of the foamable composition for various examples. [Table 16] [Table 17] [Table 18] [Table 19] [Table 20] [Table 21] [Table 22] [Table 23]

[0162] Tables 23-25 ​​provide the results of the various Examples 8G-15G that were made. The samples were measured for basis weight, seam strength, coefficient of friction and cell volume, as well as outer shell thickness and hollow core volume percent. Each of the Examples produced a medium air cell foam structure with an outer shell of foam material and a hollow interior filled with air, as seen in FIG. [Table 24] [Table 25]

[0163] The samples in Table 24 were sealed at 90 psi for 0.8 seconds at an actual temperature of 360° F. (475 set point).

[0164] In various embodiments where the seam strength was 1.0 lbf / in or greater, sufficient strength was obtained to form a mailer from the coated substrate by heat sealing the edges. Generally, the higher the seal strength, the better, with values ​​above 1.5 lbf / in being particularly preferred when shipping heavier items in mailers. [Table 26]

[0165] Coefficient of Friction Testing: The static and kinetic coefficients of friction of the discrete foamed cell coated on paper were determined using the procedure outlined in ASTM D1894-14 "Standard Test Method for Static and Kinetic Coefficients of Friction of Plastic Film and Sheeting". The test setup was according to setup C (moving sled - fixed flat surface) described in ASTM 1894-14 using an Instron Coefficient of Friction Tester part number 2810-005 (available from Instron, Norwood MA, USA) using a 100N load cell and tested on an Instron Universal Testing Load Frame 5564 (available from Instron, Norwood MA, USA). The specimens were tested against steel plates having either a mirror or matte finish. Prior to testing, the steel plates were wiped with 70 / 30 isopropyl alcohol / water. Prior to testing, the specimens were conditioned overnight in a temperature and humidity controlled room at 22.8±1.1°C (73.1±2°F) and 50±2% relative humidity. Specimens were cut to the appropriate dimensions as outlined in ASTM and attached to a moving sled. The sled weight was 200g±5g including the attached specimen. Specimens were tested using a crosshead speed of 6 inches / minute. Samples were tested in triplicate. The dynamic and static coefficients of friction were recorded and average values ​​are reported.

[0166] For foamed substrates that are formed into mailers, a lower coefficient of friction is desirable for inserting items into the mailer and for moving the foamed substrate through a processing line. In preferred embodiments, the kinetic COF can be less than 2.0, or less than 1.5, or less than 1.0, and greater than 0.0.

[0167] In the rotogravure coating process, the foamable composition is deposited on the substrate in an array of liquid dots. In other embodiments, a substantially continuous coating can be applied to the substrate first or simultaneously with the array of liquid dots. In one embodiment, a 55 lb (85 gsm) Kraft paper substrate was used. The diameter and height of the dots can vary as a function of the coating process parameters, including the individual cell volumes within the pattern, and the particular rotogravure pattern utilized. In one embodiment, the rotogravure cells form an array of liquid dots that are half of a 4 mm diameter sphere. The deposited liquid dots are dried in an oven and foamed during the drying process to create foam cells that include an outer shell of foam material and a hollow center or core filled with air. During drying, it is believed that the foamable composition, the outer surface skin in the oven, and any residual water in the composition at least partially evaporate into the center of the dot structure and exit through the substrate, creating the final hollow core structure seen in FIG. 17. In particular, it has been found that slowing the web speed through the oven after the rotogravure printing process on the substrate is necessary to form the skin layer and maximum hollow core volume within the foam cells.

[0168] Hollow foam cell structures have the advantage of creating a larger overall structure for a given amount of deposited foamable composition than can be obtained with non-hollow core foam structures. Because they have an air-filled center, the final dried foam material is concentrated and utilized only in the outer shell of the structure. The resulting foam-coated overall substrate is very similar to a renewable version of plastic (polyethylene) bubble wrap. It has the pleasant calculated feel and good cushioning properties that come from the hollow air-filled core of the foam cells, just like plastic bubble wrap.

[0169] The resulting foam cells have a structure including an outer foam shell having a thickness ranging from 25 to 500 microns, or 50 to 400 microns, or 75 to 250 microns. In various Examples 8G to 15G, the thickness of the outer foam shell was measured to be 50 to 250 microns. The resulting foam cells have a thickness ranging from 2 to 5000 mm. 3 , or 3 to 1000 mm 3 , or 5~500mm 3 , or 6~150mm 3 In various embodiments 8G-15G, the hollow core volume is between 10 and 15 mm. 3 The hollow core or hollow center volume as a percentage of the total foam cell volume can range from 5-95%, or 5-75%, or 10-50%, or 15-45% of the total foam cell volume. In various Examples 8G-15G, the hollow core volume percentage was calculated to be 81%-87%.

[0170] Various modifications and alterations to this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of the disclosure. It is to be understood that this disclosure is not intended to be unduly limited by the exemplary embodiments and examples described herein, and that such examples and embodiments are presented only as examples within the scope of this disclosure, which is intended to be limited only by the claims set forth herein as follows. All references cited in this disclosure are incorporated herein by reference in their entirety.

Claims

1. A foam padded material comprising: a sheet material having first and second major surfaces, the sheet material comprising a renewable material; a foam composition disposed on the first major surface of the sheet material; The foamable composition includes a polymer component including a hydroxy-ethylene-butylene copolymer including divalent hydroxyethylene monomer units and divalent dihydroxybutylene monomer units; A foam padded material, wherein said foam composition is in the form of an at least partially water soluble foam.

2. The foam padded material of claim 1 , wherein the foam composition is arranged in a discontinuous pattern comprising an array of discrete elements.

3. The foam padded material of claim 2 , wherein the elements comprise one or more geometric shapes including squares, rectangles, triangles, spirals, lines, circles, and the like.

4. 10. The foam padded material of claim 1, wherein said renewable materials include repulpable materials, said repulpable materials including repulpable paper.

5. 5. The foam padded material of claim 4, wherein the repulpable paper is selected from the group of fiberboard, chipboard, corrugated board, corrugated medium, solid bleached board (SBB), solid bleached sulfite board (SBS), solid unbleached board (SLB), white-lined chipboard (WLC), kraft paper, kraft board, coated paper, binder board, or mixtures thereof.

6. 10. The foam padded material of claim 1, wherein said foam composition covers at least 10% and at most 90% of the surface area of ​​said sheet material.

7. 2. The foam padded material of claim 1, wherein said hydroxy-ethylene-butylene copolymer comprises dihydric hydroxyethylene monomer units and 3,4-dihydroxybutane-1,2-diyl monomer units.

8. The foam padded material of claim 1 , wherein said polymer component further comprises a second polymer.

9. 9. The foam padded material of claim 8, wherein the second polymer is selected from the group of butanediol vinyl alcohol polymer or copolymer, starch, vinyl acetate / ethylene copolymer, polyvinyl acetate, polyvinyl alcohol, dextrin stabilized polyvinyl acetate, vinyl alcohol / vinyl acetate copolymer, vinyl alcohol / vinyl acetate / ethylene copolymer, stabilized polyvinyl acrylate copolymer, vinyl (meth)acrylic, styrene (meth)acrylic, (meth)acrylic, styrene butyl rubber, natural rubber, styrene block copolymer, polyurethane, and mixtures thereof.

10. The foam padded material of claim 1 further comprising expanding microspheres in combination with said polymeric component.

11. A packaging article comprising the foam padded material of any one of claims 1 to 10.

12. 12. The packaging article of claim 11 in the form of an envelope.

13. The packaging article of claim 11, a first wall having a first inner surface and a first outer surface opposite the first inner surface; a second wall having a second inner surface and a second outer surface opposite the second inner surface, the first and second inner surfaces defining an interior of the packaged article and the first and second outer surfaces defining an exterior of the packaged article; a foam composition disposed on at least a portion of each of the first and second interior surfaces; a seal joint at one or more edges of the first and second walls, the seal joint comprising the foam composition and attaching the first wall to the second wall; the first and second walls comprise renewable materials; The foamable composition includes a polymer component including a hydroxy-ethylene-butylene copolymer including divalent hydroxyethylene monomer units and divalent dihydroxybutylene monomer units; The packaging article, wherein the foam composition is in the form of an at least partially water soluble foam.

14. 14. The packaging article of claim 13, wherein the first wall further comprises a flap adapted to fold between an open configuration and a closed configuration, the flap extending beyond the opening of the packaging article in the open configuration and covering the opening of the packaging article in the closed configuration.

15. The packaging article of claim 14 , wherein the flap has at least one adhesive portion disposed thereon.

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