Foamable composition with ethylene-vinyl acetate recycled foam and foam article made therefrom

Abstract

Embodiments are directed to a foamable composition comprising virgin ethylenevinyl acetate, greater than or equal to 15 phr ethylene-vinyl acetate recycled foam, elastomer, polarity modifier, a crosslinking agent, and a blowing agent. The elastomer comprises ethylene / alpha-olefin multi-block interpolymer, ethylene / alpha-olefin copolymer, or combinations thereof. The polarity modifier comprises ethylene-alkyl (meth)acrylate copolymer. Further embodiments are directed to foam articles comprising the foamable composition and processes for manufacturing the foam articles.

Description

[0001] FOAMABLE COMPOSITION WITH ETHYLENE-VINYL ACETATE RECYCLED FOAM AND FOAM ARTICLE MADE THEREFROM

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] [1] This application claims the benefit of U.S. Provisional Application Serial No.

[0004] 63 / 711,852 filed October 25, 2024, the contents of which are incorporated in their entirety herein.

[0005] TECHNICAL FIELD

[0006] [2] Embodiments of the present disclosure generally relate to formable compositions and specifically relate to foamable compositions including ethylene-vinyl acetate recycled foam used to form foam articles having desired bond strength and other desirable mechanical properties.

[0007] BACKGROUND

[0008] [3] Ethylene-vinyl acetate is commonly used in footwear applications such as athletic shoe midsoles, casual shoe soles, insoles, or mono-block shoes (i.e., whole shoes made of a single compound). Polyolefin elastomers, such as ethylene-alpha-olefin copolymers and olefin block copolymers, are included to modify the ethylene-vinyl acetate and to improve mechanical properties of the composition, such as static compression set, shrinkage, hardness, and rebound resilience. Due to environmental and sustainability efforts, it may be desirable to include pre-consumer recycled polymer or post-consumer recycled polymers in footwear compositions. However, using compositions with increased recycled content may result in articles having undesirable bond strength and / or other undesirable mechanical properties.

[0009] [4] Accordingly, there is a need for improved foamable compositions having increased recycled content and that may be used to achieve foam articles having desirable bond strength and other desirable mechanical properties.

[0010] SUMMARY

[0011] [5] The embodiments of the present disclosure meet this need by utilizing a combination of virgin ethylene-vinyl acetate, ethylene-vinyl acetate recycled foam, elastomer, polarity modifier, a crosslinking agent, and a blowing agent. This resulted in a foamable composition having increased recycled content and that may be used to form a foam article having desirable bond strength (e.g., a bond strength greater than or equal to 2.0 N / mm) and other desirable mechanical properties (e.g., a static compression set from 40% to 90%; a shrinkage from 0.1% to 3%; a hardness from 30 Shore A to 50 Shore A; and a rebound resilience from 35% to 65%. )

[0012] [6] In one embodiment, a foamable composition comprises: virgin ethylene- vinyl acetate; greater than or equal to 15 phr ethylene-vinyl acetate recycled foam; elastomer, the elastomer comprising ethylene / alpha-olefin multi-block interpolymer, ethylene / alpha-olefin copolymer, or combinations thereof; polarity modifier, the polarity modifier comprising ethylene-alkyl (meth)acrylate copolymer; a crosslinking agent; and a blowing agent.

[0013] [7] In another embodiment, a process of manufacturing a foam article comprises: mixing a foamable composition at a temperature from 120 °C to 130 °C, the foamable composition comprising: virgin ethylene-vinyl acetate; greater than or equal to 15 phr ethylene-vinyl acetate recycled foam; elastomer, the elastomer comprising ethylene / alpha-olefin multi-block interpolymer, ethylene / alpha-olefin copolymer, or combinations thereof; polarity modifier, the polarity modifier comprising ethylene-alkyl (meth)acrylate copolymer; a crosslinking agent; and a blowing agent; and forming a foam article from the foamable composition, wherein the foam article comprises at least one of the following: a static compression set from 40% to 90%; a shrinkage from 0.1% to 3%; a hardness from 30 Shore A to 50 Shore A; and a rebound resilience from 35% to 65%.

[0014] [8] Additional features and advantages will be set forth in the detailed description, which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows and the claims.

[0015] [9] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter.

[0016] BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

[0017]

[0011] FIG. 1 schematically illustrates a foam article, according to one or more embodiments described in this disclosure.

[0018]

[0012] Reference will now be made in detail to various embodiments, some embodiments of which are illustrated in the accompanying drawings.

[0019] DETAILED DESCRIPTION

[0020]

[0013] Specific embodiments of the present application will now be described. The disclosure may be embodied in different forms and should not be construed as limited to the embodiments set forth in this disclosure. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art.

[0021]

[0014] DEFINITIONS

[0022]

[0015] Unless stated to the contrary, implicit from the context, or customary in the art, all test methods are current as of the filing date of this disclosure.

[0023]

[0016] The amount of a component (virgin ethylene- vinyl acetate, ethylene- vinyl acetate recycled foam, elastomer, polarity modifier, a crosslinking agent, and a blowing agent) is provided here in parts by weight (“phr”) of the identified component per 100 parts resin (i.e., virgin ethylene-vinyl acetate, ethylene-vinyl acetate recycled foam, elastomer, polarity modifier), herein referred to as “phr.”

[0024]

[0017] Ranges may be expressed herein as from “about” one particular value, and / or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0025]

[0018] The term "polymer" refers to a material prepared by reacting (i.e., polymerizing) a set of monomers, wherein the set is a homogenous (i.e., only one type) set of monomers or a heterogeneous (z.e., more than one type) set of monomers. The generic term polymer as used herein includes the term "homopolymer," which refers to polymers prepared from a homogenous set of monomers, and the term "interpolymer" as defined below.

[0026]

[0019] The term “homopolymer” is employed to refer to polymers prepared from only one type of monomer, with the understanding that trace amounts of impurities can be incorporated into the polymer structure.

[0027]

[0020] The term "interpolymer" refers to a polymer prepared by the polymerization of at least two different types of monomers. This term includes both “copolymers,” i.e., polymers prepared from two different types of monomers, and polymers prepared from more than two different types of monomers, e.g., terpolymers, tetrapolymers, etc. This term also embraces all forms of interpolymers, such as random, block, homogeneous, heterogeneous, etc.

[0028]

[0021] The term “ethylene / alpha-olefin interpolymer,” as used herein, refers to a polymer that comprises, in polymerized form, a majority weight percent of ethylene (based on the weight of the interpolymer), and at least one comonomer that is an alpha-olefin. The ethylene / alpha-olefin interpolymer may be a random or block interpolymer. The terms “ethylene / alpha-olefin copolymer” and “ethylene / alpha-olefin multi-block interpolymer” are covered by the term “ethylene / alpha-olefin interpolymer.”

[0029]

[0022] The term “ethylene / alpha-olefin copolymer,” as used herein, refers to a copolymer that comprises, in polymerized form, a majority weight percent of ethylene (based on the weight of the copolymer), and a comonomer that is an alpha-olefin, where ethylene and the alpha-olefin are the only two monomer types. The ethylene / alpha-olefin copolymer does not exclude residual amounts of other components. The ethylene / alpha-olefin copolymer may be a random or block copolymer.

[0030]

[0023] The term “elastomer” refers to a polymer with viscoelasticity (having both viscosity and elasticity) and weak inter-molecular forces, generally having low Young’s modulus and high failure strain compared with other materials. An elastomer has the property of elasticity, i.e., the elastomer is a polymer that deforms under stress and returns to its original shape when stress is removed, having long flexible chain-like molecules with high mobility above its Tg(glass transition temperature).

[0031]

[0024] “Recycled resins” (e.g., ethylene-vinyl acetate recycled foam) refers to resins, which were incorporated into products and subsequently re-melted to form a recycled resin. The term “recycled resins” refers to mechanically recycled resins, where the resin is melted and reincorporated into a new product. “Recycled resins” does not include chemically recycled resins, where the polymer is broken down into constituent monomers and incorporated into a new virgin polymer. The term “recycled resins” embraces both post-industrial recycled polymer and post-consumer resin. Recycled resins are defined in ISO 14021 7.8.1.1.

[0032]

[0025] The term “post-industrial recycled (PIR) polymer” refers to polymers that are reclaimed from manufacturing processes and never reach consumers. PIR is collected from excess trim, scraps, or defective products within a manufacturing facility. PIR is generated in a process and capable of being reclaimed within the same process that generated it.

[0033]

[0026] The term “post-consumer resin” (or “PCR”), as used herein, refers to a polymeric material that includes materials previously used in a consumer or industry application (i.e., post-industrial recycled polymer). PCR is typically collected from recycling programs and recycling plants. The PCR may include one or more contaminants. The contaminants may be the result of the polymeric material’s use prior to being repurposed for reuse. For example, contaminants may include paper, ink, food residue, or other recycled materials in addition to the polymer, which may result from the recycling process. PCR is distinct from virgin polymeric material. A virgin polymeric material (such as a virgin ethylene-vinyl acetate) does not include materials previously used in a consumer or industry application. Virgin polymeric material has not undergone, or otherwise has not been subject to, a heat process or a molding process, after the initial polymer manufacturing process. The physical, chemical, and flow properties of PCR resins differ when compared to virgin polymeric resin, which in turn can present challenges to incorporating PCR into formulations for commercial use. Postconsumer resin is defined in ISO 14021 7.8.1.1.

[0034]

[0027] The terms "comprising", "including", "having”, and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term, "consisting essentially of’ excludes from the scope of any succeeding recitation any other component, step or procedure, excepting those that are not essential to operability. The term "consisting of’ excludes any component, step or procedure, not specifically delineated or listed.

[0028] EMBODIMENTS

[0035]

[0029] Embodiments of the present disclosure are directed to foamable compositions comprising virgin ethylene-vinyl acetate, ethylene-vinyl acetate recycled foam, elastomer, polarity modifier, a crosslinking agent, and a blowing agent.

[0036]

[0030] Virgin Ethylene-vinyl Acetate

[0037]

[0031] Virgin ethylene-vinyl acetate helps to impart desirable bond strength and other desirable mechanical properties to the resulting foam article.

[0038]

[0032] A minimum amount of virgin ethylene-vinyl acetate (e.g., greater than or equal to 30 phr) may be included in the foamable composition to form a foam article having a desirable bond strength and other desirable mechanical properties. The amount of virgin ethylenevinyl acetate may be limited (e.g., less than or equal to 78 phr) to ensure that other components may be included in certain amounts to impart desired properties. Accordingly, in embodiments, the foamable composition may comprise from 30 phr to 78 phr virgin ethylene-vinyl acetate. In embodiments, the amount of virgin ethylene-vinyl acetate in the foamable composition may be greater than or equal to 30 phr, greater than or equal to 35 phr, greater than or equal to 40 phr, greater than or equal to 45 phr, or even greater than or equal to 50 phr. In embodiments, the amount of virgin ethylene-vinyl acetate in the foamable composition may be less than or equal to 78 phr, less than or equal to 75 phr, less than or equal to 70 phr, less than or equal to 65 phr, or even less than or equal to 60 phr. In embodiments, the amount of the virgin ethylene-vinyl acetate in the foamable composition may be from 30 phr to 78 phr, from 30 phr to 75 phr, from 30 phr to 70 phr, from 30 phr to 65 phr, from 30 phr to 60 phr, from 35 phr to 78 phr, from 35 phr to 75 phr, from 35 phr to 70 phr, from 35 phr to 65 phr, from 35 phr to 60 phr, from 40 phr to 78 phr, from 40 phr to 75 phr, from 40 phr to 70 phr, from 40 phr to 65 phr, from 40 phr to 60 phr, from 45 phr to 78 phr, from 45 phr to 75 phr, from 45 phr to 70 phr, from 45 phr to 65 phr, from 45 phr to 60 phr, from 50 phr to 78 phr, from 50 phr to 75 phr, from 50 phr to 70 phr, from 50 phr to 65 phr, or even from 50 phr to 60 phr, or any and all sub-ranges from any of these endpoints.

[0039]

[0033] The virgin ethylene-vinyl acetate may have a minimum vinyl acetate level (e.g., greater than or equal to 10 wt%) to achieve a foam article having a desirable bond strength and other desirable mechanical properties. Accordingly in embodiments, the virgin ethylenevinyl acetate may comprise a vinyl acetate level from 10 wt% to 35 wt%. In embodiments, the virgin ethylene-vinyl acetate may comprise a vinyl acetate level greater than or equal to 10 wt%, greater than or equal to 12 wt%, greater than or equal to 14 wt%, greater than or equal to 16 wt%, or even greater than or equal to 18 wt%. In embodiments, the virgin ethylene- vinyl acetate may comprise a vinyl acetate level less than or equal to 35 wt%, less than or equal to 32 wt%, less than or equal to 30 wt%, less than or equal to 28 wt%, less than or equal to 26 wt%, less than or equal to 24 wt%, less than or equal to 22 wt%, or even less than or equal to 20 wt%. In embodiments, the virgin ethylene-vinyl acetate may comprise a vinyl acetate level from 10 wt% to 35 wt%, from 10 wt% to 32 wt%, from 10 wt% to 30 wt%, from 10 wt% to 28 wt%, from 10 wt% to 26 wt%, from 10 wt% to 24 wt%, from 10 wt% to 22 wt%, from 10 wt% to 20 wt%, from 12 wt% to 35 wt%, from 12 wt% to 32 wt%, from 12 wt% to 30 wt%, from 12 wt% to 28 wt%, from 12 wt% to 26 wt%, from 12 wt% to 24 wt%, from 12 wt% to 22 wt%, from 12 wt% to 20 wt%, from 14 wt% to 35 wt%, from 14 wt% to 32 wt%, from 14 wt% to 30 wt%, from 14 wt% to 28 wt%, from 14 wt% to 26 wt%, from 14 wt% to 24 wt%, from 14 wt% to 22 wt%, from 14 wt% to 20 wt%, from 16 wt% to 35 wt%, from 16 wt% to 32 wt%, from 16 wt% to 30 wt%, from 16 wt% to 28 wt%, from 16 wt% to 26 wt%, from 16 wt% to 24 wt%, from 16 wt% to 22 wt%, from 16 wt% to 20 wt%, from 18 wt% to 35 wt%, from 18 wt% to 32 wt%, from 18 wt% to 30 wt%, from 18 wt% to 28 wt%, from 18 wt% to 26 wt%, from 18 wt% to 24 wt%, from 18 wt% to 22 wt%, or even from 18 wt% to 20 wt%, or any and all sub-ranges formed from any of these endpoints.

[0040]

[0034] In embodiments, the virgin ethylene-vinyl acetate may comprise a density from 0.935 g / cm3to 0.965 g / cm3. In embodiments, the virgin ethylene-vinyl acetate may comprise a density greater than or equal to 0.935 g / cm3or even greater than or equal to 0.940 g / cm3. In embodiments, the virgin ethylene-vinyl acetate may comprise a density less than or equal to 0.965 g / cm3, less than or equal to 0.960 g / cm3, less than or equal to 0.955 g / cm3, or even less than or equal to 0.950 g / cm3. In embodiments, the virgin ethylene-vinyl acetate may comprise a density from 0.935 g / cm3to 0.965 g / cm3, from 0.935 g / cm3to 0.960 g / cm3, from 0.935 g / cm3to 0.955 g / cm3, from 0.935 g / cm3to 0.950 g / cm3, from 0.940 g / cm3to 0.965 g / cm3, from 0.940 g / cm3to 0.960 g / cm3, from 0.940 g / cm3to 0.955 g / cm3, or even from 0.940 g / cm3to 0.950 g / cm3, or any and all sub-ranges formed from any of these endpoints.

[0041]

[0035] In embodiments, the virgin ethylene-vinyl acetate may comprise a melt index (MI) from 2 g / 10 min to 60 g / min. In embodiments, the virgin ethylene-vinyl acetate may comprise a melt index (MI) greater than or equal to 2 g / 10 min, greater than or equal to 5 g / 10 min, greater than or equal to 10 g / 10 min, or even greater than or equal to 20 g / 10 min. In embodiments, the virgin ethylene-vinyl acetate may comprise a melt index (MI) less than or equal to 60 g / min, less than or equal to 40 g / 10 min, less than or equal to 20 g / 10 min, less than or equal to 10 g / 10 min, or even less than or equal to 5 g / 10 min. In embodiments, the virgin ethylene-vinyl acetate may comprise a melt index (MI) from 2 g / 10 min to 60 g / min, from 2 g / 10 min to 40 g / min, from 2 g / 10 min to 20 g / min, from 2 g / 10 min to 10 g / min, from 2 g / 10 min to 5 g / min, from 5 g / 10 min to 60 g / min, from 5 g / 10 min to 40 g / min, from 5 g / 10 min to 20 g / min, from 5 g / 10 min to 10 g / min, from 10 g / 10 min to 60 g / min, from 10 g / 10 min to 40 g / min, from 10 g / 10 min to 20 g / min, from 20 g / 10 min to 60 g / min, or even from 20 g / 10 min to 40 g / min, or any and all sub-ranges formed from any of these endpoints.

[0042]

[0036] Suitable commercial embodiments of the virgin ethylene-vinyl acetate may be available from The Dow Chemical Company under the ELVAX™ brand, such as grade 250A.

[0043]

[0037] Ethylene-vinyl Acetate Recycled Foam

[0044]

[0038] Ethylene-vinyl acetate recycled foam increases the recycled content of the foamable composition and helps to achieve foam article having a desirable bond strength and other desirable mechanical properties. The ethylene-vinyl acetate recycled foam may be in the form of an expanded and crosslinked grounded powder.

[0045]

[0039] The foamable composition may comprise a minimum amount of ethylene-vinyl acetate recycled foam (e.g., greater than or equal to 15 phr) to achieve an increased recycled content. The amount of ethylene-vinyl acetate recycled foam may be limited (e.g., less than or equal to 40 phr) to ensure that a foam article having a desirable bond strength and other desirable mechanical properties is achieved. Accordingly, in embodiments, the foamable composition may comprise from 15 phr to 40 phr of the ethylene-vinyl acetate recycled foam. In embodiments, the amount of the ethylene-vinyl acetate recycled foam in the foamable composition may be greater than or equal to 15 phr, greater than or equal to 20 phr, or even greater than or equal to 25 phr. In embodiments, the amount of the ethylene-vinyl acetate recycled foam in the foamable composition may be less than or equal to 40 phr, less than or equal to 35 phr, less than or equal to 30 phr, or even less than or equal to 25 phr. In embodiments, the amount of the ethylene-vinyl acetate recycled foam in the foamable composition may be from 15 phr to 40 phr, from 15 phr to 35 phr, from 15 phr to 30 phr, from 15 phr to 25 phr, from 20 phr to 40 phr, from 20 phr to 35 phr, from 20 phr to 30 phr, from 20 phr to 25 phr, from 25 phr to 40 phr, from 25 phr to 35 phr, or even from 25 phr to 30 phr, or any and all sub-ranges formed from any of these endpoints.

[0046]

[0040] In embodiments, the recycled ethylene vinyl acetate may comprise a density from 0.20 g / cm3to 0.29 g / cm3. In embodiments, the recycled ethylene vinyl acetate may comprise a density greater than or equal to 0.20 g / cm3, greater than or equal to 0.23 g / cm3, or even greater than or equal to 0.25 g / cm3. In embodiments, the recycled ethylene vinyl acetate may comprise a density less than or equal to 0.29 g / cm3or even less than or equal to 0.27 g / cm3. In embodiments, the recycled ethylene vinyl acetate may comprise a density from 0.20 g / cm3to 0.29 g / cm3, from 0.20 g / cm3to 0.27 g / cm3, from 0.23 g / cm3to 0.29 g / cm3, from 0.23 g / cm3to 0.27 g / cm3, from 0.25 g / cm3to 0.29 g / cm3, or even from 0.25 g / cm3to 0.27 g / cm3, or any and all sub-ranges formed from any of these endpoints.

[0047]

[0041] Elastomer

[0048]

[0042] Elastomer modifies the ethylene-vinyl acetate included in the foamable composition, thereby achieving a foam article having desirable bond strength and other desirable mechanical properties.

[0049]

[0043] The elastomer may comprise ethylene / alpha-olefin multi-block interpolymer, ethylene / alpha-olefin copolymer, or combinations thereof. In embodiments, the ethylene / alpha-olefin multi-block interpolymer may comprise an olefin block copolymer. In embodiments, the ethylene / alpha-olefin copolymer may comprise ethylene-octene copolymer. The alpha-olefin monomer may comprise C3-C10 alpha-olefin.

[0050]

[0044] The foamable composition may comprise a minimum amount of the elastomer (e.g., greater than or equal to 1 phr) to ensure that the resulting foam article has a desirable bond strength and other desirable mechanical properties. Accordingly, in embodiments, the foamable composition may comprise from 1 phr to 40 phr of the elastomer. In embodiments, the amount of the elastomer in the foamable composition may be greater than or equal to 1 phr, greater than or equal to 5 phr, greater than or equal to 10 phr, or ever greater than or equal to 15 phr. In embodiments, the amount of the elastomer in the foamable composition may be less than or equal to 40 phr, less than or equal to 30 phr, or even less than or equal to 20 phr. In embodiments, the amount of the elastomer in the foamable composition may be from 1 phr to 40 phr, from 1 phr to 30 phr, from 1 phr to 20 phr, from 5 phr to 40 phr, from 5 phr to 30 phr, from 5 phr to 20 phr, from 10 phr to 40 phr, from 10 phr to 30 phr, from 10 phr to 20 phr, from 15 phr to 40 phr, from 15 phr to 30 phr, or even from 15 phr to 20 phr, or any and all sub-ranges formed from any of these endpoints.

[0051]

[0045] In embodiments, the elastomer may comprise a density from 0.850 g / cm3to 0.890 g / cm3. In embodiments, the elastomer may comprise a density greater than or equal to 0.850 g / cm3, greater than or equal to 0.860 g / cm3, or even greater than or equal to 0.870 g / cm3. In embodiments, the elastomer may comprise a density less than or equal to 0.890 g / cm3or even less than or equal to 0.880 g / cm3. In embodiments, the elastomer may comprise a density from 0.850 g / cm3to 0.890 g / cm3, from 0.850 g / cm3to 0.880 g / cm3, from 0.860 g / cm3to 0.890 g / cm3, from 0.860 g / cm3to 0.880 g / cm3, from 0.870 g / cm3to 0.890 g / cm3, or even from 0.870 g / cm3to 0.880 g / cm3, or any and all sub-ranges formed from any of these endpoints.

[0052]

[0046] In embodiments, the elastomer may comprise a melt index (MI) from 0.5 g / 10 min to 50 g / 10 min. In embodiments, the elastomer may comprise a melt index (MI) greater than or equal to 0.5 g / 10 min, greater than or equal to 1 g / 10 min, greater than or equal to 3 g / 10 min, or even greater than or equal to 5 g / 10 min. In embodiments, the elastomer may comprise a melt index (MI) less than or equal to 50 g / 10 min, less than or equal to 40 g / 10 min, less than or equal to 30 g / 10 min, less than or equal to 20 g / 10 min, or even less than or equal to 10 g / 10 min. In embodiments, the elastomer may comprise a melt index (MI) from 0.5 g / 10 min to 50 g / 10 min, from 0.5 g / 10 min to 40 g / 10 min, from 0.5 g / 10 min to 30 g / 10 min, from 0.5 g / 10 min to 20 g / 10 min, from 0.5 g / 10 min to 10 g / 10 min, from 1 g / 10 min to 50 g / 10 min, from 1 g / 10 min to 40 g / 10 min, from 1 g / 10 min to 30 g / 10 min, from 1 g / 10 min to 20 g / 10 min, from 1 g / 10 min to 10 g / 10 min, from 3 g / 10 min to 50 g / 10 min, from 3 g / 10 min to 40 g / 10 min, from 3 g / 10 min to 30 g / 10 min, from 3 g / 10 min to 20 g / 10 min, from 3 g / 10 min to 10 g / 10 min, from 5 g / 10 min to 50 g / 10 min, from 5 g / 10 min to 40 g / 10 min, from 5 g / 10 min to 30 g / 10 min, from 5 g / 10 min to 20 g / 10 min, or even from 5 g / 10 min to 10 g / 10 min, or any and all sub-ranges formed from any of these endpoints.

[0053]

[0047] Suitable commercial embodiments of the ethylene / alpha-olefin multi-block interpolymer may be available from The Dow Chemical Company under the INFUSE™ brand, such as olefin block copolymer grade 9500.

[0048] Suitable commercial embodiments of the ethylene-alpha-olefin copolymer may be available from The Dow Chemical Company under the ENGAGE™ brand, such as ethyleneoctene copolymer grade 8200.

[0054]

[0049] Polarity Modifier

[0055]

[0050] Polarity modifier ensures sufficient blending and compatibility such that the resulting foam article has a desirable bond strength and other desirable mechanical properties.

[0056]

[0051] In embodiments, the polarity modifier may comprise ethylene-alkyl (meth)acrylate copolymer, “ethylene-alkyl (meth)acrylate copolymer” refers to a copolymer of ethylene and an alkyl (meth) acrylate. “(Meth)acrylate refers to an acrylate and / or a methacrylate. For example, in some embodiments, alkyl (meth)acrylate may include methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, or combinations thereof. In embodiments, ethylene-alkyl (meth)acrylate copolymer may comprise ethylene-methyl acrylate, ethylene-butyl acrylate, or combinations thereof.

[0057]

[0052] A minimum amount of polarity modifier (e.g., greater than or equal to 1 phr) may be included in the foamable composition to ensure sufficient blending and compatibility is achieved to form a foam article having desirable bond strength and other desirable mechanical properties. Accordingly, in embodiments, the foamable composition may comprise from 1 phr to 30 phr of the polarity modifier. In embodiments, the amount of the polarity modifier in the foamable composition may be greater than or equal to 1 phr, greater than or equal to 5 phr, greater than or equal to 10 phr, or even greater than or equal to 15 phr. In embodiments, the amount of the polarity modifier in the foamable composition may be less than or equal to 30 phr, less than or equal to 25 phr, or even less than or equal to 20 phr. In embodiments, the amount of the polarity modifier in the foamable composition may be from 1 phr to 30 phr, from 1 phr to 25 phr, from 1 phr to 20 phr, from 5 phr to 30 phr, from 5 phr to 25 phr, from 5 phr to 20 phr, from 10 phr to 30 phr, from 10 phr to 25 phr, from 10 phr to 20 phr, from 15 phr to 30 phr, from 15 phr to 25 phr, or even from 15 phr to 20 phr, or any and all sub-ranges formed from any of these points.

[0058]

[0053] In embodiments, the polarity modifier may comprise a density from 0.920 g / cm3to 0.960 g / cm3. In embodiments, the polarity modifier may comprise a density greater than or equal to 0.920 g / cm3, greater than or equal to 0.930 g / cm3, or even greater than or equal to 0.940 g / cm3. In embodiments, the polarity modifier may comprise a density less than or equal to 0.960 g / cm3or even less than or equal to 0.950 g / cm3. In embodiments, the polarity modifier may comprise a density from 0.920 g / cm3to 0.960 g / cm3, from 0.920 g / cm3to 0.950 g / cm3, from 0.930 g / cm3to 0.960 g / cm3, from 0.930 g / cm3to 0.950 g / cm3, from 0.940 g / cm3to 0.960 g / cm3, or even from 0.940 g / cm3to 0.950 g / cm3, or any and all sub-ranges formed from any of these endpoints.

[0059]

[0054] In embodiments, the polarity modifier may comprise a melt index (MI) from 0.5 g / 10 min to 40 g / 10 min. In embodiments, the polarity modifier may comprise a melt index (MI) greater than or equal to 0.5 g / 10 min, greater than or equal to 1 g / 10 min, greater than or equal to 2 g / 10 min, or even greater than or equal to 3 g / 10 min. In embodiments, the polarity modifier may comprise a melt index (MI) less than or equal to 40 g / 10 min, less than or equal to 30 g / 10 min, less than or equal to 20 g / 10 min, less than or equal to 10 g / 10 min, or even less than or equal to 5 g / 10 min. In embodiments, the polarity modifier may comprise a melt index (MI) from 0.5 g / 10 min to 40 g / 10 min, from 0.5 g / 10 min to 30 g / 10 min, from 0.5 g / 10 min to 20 g / 10 min, from 0.5 g / 10 min to 10 g / 10 min, from 0.5 g / 10 min to 5 g / 10 min, from 1 g / 10 min to 40 g / 10 min, from 1 g / 10 min to 30 g / 10 min, from 1 g / 10 min to 20 g / 10 min, from 1 g / 10 min to 10 g / 10 min, from 1 g / 10 min to 5 g / 10 min, from 2 g / 10 min to 40 g / 10 min, from 2 g / 10 min to 30 g / 10 min, from 2 g / 10 min to 20 g / 10 min, from 2 g / 10 min to 10 g / 10 min, from 2 g / 10 min to 5 g / 10 min, from 3 g / 10 min to 40 g / 10 min, from 3 g / 10 min to 30 g / 10 min, from 3 g / 10 min to 20 g / 10 min, from 3 g / 10 min to 10 g / 10 min, or even from 3 g / 10 min to 5 g / 10 min, or any and all sub-ranges formed from any of these endpoints.

[0060]

[0055] Suitable commercial embodiments of the ethylene-alkyl (meth)acrylate copolymer may be available from The Dow Chemical Company under the ELVALOY™ brand, such as ethylene-methyl acrylate grade 1330.

[0061]

[0056] Crosslinking Agent

[0062]

[0057] Crosslinking agent ensures sufficient crosslinking of the foamable composition to produce a foam article have desirable bond strength and other desirable mechanical properties.

[0063]

[0058] In embodiments, the crosslinking agent may comprise dicumyl peroxide.

[0064]

[0059] In embodiments, the amount of the crosslinking agent in the foamable composition may be greater than or equal to 0.1 phr, greater than or equal to 0.5 phr, or even greater than or equal to 1 phr. In embodiments, the amount of the crosslinking agent in the foamable composition may be less than or equal to 3 phr or even less than or equal to 2 phr. In embodiments, the amount of the crosslinking agent in the foamable composition may be from 0.1 phr to 3 phr, from 0.1 phr to 2 phr, from 0.5 phr to 3 phr, from 0.5 phr to 2 phr, from 1 phr to 3 phr, or even from 1 phr to 2 phr, or any and all sub-ranges formed from any of these endpoints.

[0065]

[0060] Suitable commercial embodiments of the crosslinking agent may be available from Arkema under the LUPEROX® brand, such as grades DC40P-SP2 and 101.

[0066]

[0061] Blowing Agent

[0067]

[0062] “Blowing agent” refers to a substance that is capable of producing a cellular structure in a foamable composition via a foaming process. The blowing agent is used for foaming dynamically crosslinked polymers.

[0068]

[0063] The blowing agent used in the present disclosure is not particularly limited, so long as the blowing agent can expand the crosslinked particles.

[0069]

[0064] In embodiments, the blowing agent may comprise inorganic blowing agents, organic blowing agents, chemical blowing agents, or combinations thereof.

[0070]

[0065] Non-limiting examples of suitable inorganic physical blowing agents may include carbon dioxide, nitrogen, argon, water, air, helium, oxygen, neon, or combinations thereof.

[0071]

[0066] Non-limiting examples of suitable organic physical blowing agents may include aliphatic hydrocarbons having 1-6 carbon atoms, such as methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, or combinations thereof; aliphatic alcohols having 1-3 carbon atoms, such as methanol, ethanol, n-propanol, isopropanol, or combinations thereof; alicyclic hydrocarbons, such as cyclohexane, cyclopentane, or combinations thereof; and fully and partially halogenated aliphatic hydrocarbons having 1-4 carbon atoms, such as fluorocarbons, chlorocarbons, chlorofluorocarbons, or combinations thereof.

[0072]

[0067] Non-limiting examples of suitable fluorocarbons may include methyl fluoride; perfluoromethane; ethyl fluoride; 1, 1 -difluoroethane (HFC152a); 1, 1, 1-trifluoroethane (HFC-143a); 1, 1, 1, 2-tetrafluoroethane (HFC-134a); pentafluoroethane; difluoromethane; perfluoroethane; 2, 2-difluoropropane; 1, 1, 1-trifluoropropane; perfluoropropane; 1, 1-difluoropropane; perfluorobutane; perfluorocyclobutane; chlorofluoromethane; trifluoromethane; or combinations thereof.

[0068] Non-limiting examples of suitable partially halogenated chlorocabons may include dialkyl ethers such as, dimethyl ether, diethyl ether, methyl ethyl ether, and mixtures thereof; methyl chloride; methylene chloride; ethyl chloride; 1, 1, 1 -trichloroethane; 1, 1-dichloro-l-fluoroethane (HCFC-141b); 1-chloro-l, 1-difluoroethane (HCFC-142b); 1, l-dichloro-2, 2, 2-trifluoroethane (HCFC-123); 1-chloro-l, 2, 2, 2-tetrafluoroethane (HCFC-124); dichloropropane or combinations thereof.

[0073]

[0069] Non-limiting examples of suitable fully halogenated chlorofluorocabons may include richloromonofluoromethane (OPOI 1); dichlorodifluoromethane (CFO-12); trichlorotrifluoroethane (CFO-113); dichlorotetrafluoroethane (CFO-114); chloroheptafluoropropane; dichlorohexafluoropropane; or combinations thereof.

[0074]

[0070] Non-limiting examples of suitable chemical blowing agents may include azodicarbonamide; azodiisobutyro-nitrile; benezenesulfonhydrazide; 4, 4-oxybenzene sulfonyl-semicarbazide; p-toluene sulfonyl semi-carbazide; barium azodicarboxylate; N, N'-dimethyl-N, N'-dinitrosoterephthalamide; trihydrazino triazine; or combinations thereof.

[0075]

[0071] In embodiments, the blowing agent may comprise azodicarbonamide.

[0076]

[0072] In embodiments, the amount of the blowing agent in the foamable composition may be greater than or equal to 0.5 phr, greater than or equal to 1 phr, or even greater than or equal to 2 phr. In embodiments, the amount of the blowing agent in the foamable composition may be less than or equal to 5 phr, less than or equal to 4 phr, or even less than or equal to 3 phr. In embodiments, the amount of the blowing agent in the foamable composition may be from 0.5 phr to 5 phr, from 0.5 to 4 phr, from 0.5 to 3 phr, from 1 phr to 5 phr, from 1 to 4 phr, from 1 to 3 phr, from 2 phr to 5 phr, from 2 to 4 phr, or even from 2 to 3 phr, or any and all sub-ranges formed from any of these endpoints.

[0077]

[0073] Suitable commercial embodiments of the blowing agent are available from DONG JIN SEMICHEM under the UNICELL-D brand, such as azodicarbonamide grade 300.

[0078]

[0074] Additives

[0079]

[0075] The foamable composition may further include optional additives to perform specific functions while still achieving a foam article having a desirable bond strength and other desirable mechanical properties. In embodiments, the additives may comprise accelerator, filler, or combinations thereof.

[0076] In embodiments, the accelerator may comprise zinc oxide (ZnO), zinc stearate (ZnSt), or combinations thereof. In embodiments, the amount of the accelerator in the foamable composition may be from 0.1 phr to 5 phr, from 0.1 phr to 4 phr, from 0.1 phr to 3 phr, from 0.1 phr to 2 phr, from 0.5 phr to 5 phr, from 0.5 phr to 4 phr, from 0.5 phr to 3 phr, from 0.5 phr to 2 phr, from 1 phr to 5 phr, from 1 phr to 4 phr, from 1 phr to 3 phr, or even from 1 phr to 2 phr, or any and all sub-ranges formed from any of these endpoints.

[0080]

[0077] In embodiments, the filler may comprise calcium carbonate (CaCCh), nucleating agents, antioxidants, pigments, colorants such as titanium oxide (TiCh) to provide white color, UV stabilizers, UV absorbers, processing aids, compatibilizers, other polymer resins, or combinations thereof. In embodiments, the amount of the filler in the foamable composition may be from 1 phr to 10 phr, from 1 phr to 8 phr, from 1 phr to 6 phr, from 3 phr to 10 phr, from 3 phr to 8 phr, from 3 phr to 6 phr, from 5 phr to 10 phr, from 5 phr to 8 phr, or even from 5 phr to 6 phr, or any and all sub-ranges formed from any of these endpoints.

[0081]

[0078] Foam Article

[0082]

[0079] The foamable compositions described herein may be used to form a foam article having desirable bond strength and other desirable mechanical properties. In embodiments, the foam article may be used in footwear applications, wherein the foam article is incorporated into footwear such as shoe parts used in the footwear industry.

[0083]

[0080] Referring now to FIG. 1, a multilayer structure is shown at 100. The multilayer structure 10 includes a foam layer 102 bonded to a polar material layer 104. A primer layer 106 and an adhesive layer 108 may be disposed between the foam layer 102 and the polar layer 104, thereby bonding the foam layer 102 to the polar material layer 104. In embodiments, the polar material layer 104 may comprise polyvinyl chloride (PVC).

[0084]

[0081] As mentioned herein, the foam article may have desirable bond strength and other desirable mechanical properties. What is “desirable” may depend on the application of the foam article. Certain properties may be desirable, for example, sports shoes, while other properties may be desirable for dress shoes. For example, low compression set may be desireable for sports shoes, but not as important for dress shoes.

[0085]

[0082] Bonding performance is generally important analysis to a shoe manufacturer. For example, if bonding of a midsole to the upper part of a shoe is insufficient, the whole shoe developed may fail, even if the other properties of the shoe are achieved. Insufficient bonding is a consequential type of failure because such a failure may occur when a customer is using the shoe.

[0086]

[0083] In embodiments, the foam article may comprise a bond strength greater than or equal to 2.0 N / mm, greater than or equal to 2.3 N / mm, or even greater than or equal 2.5 N / mm. According to the Brazilian Institute of Technology for Leather, Footwear, and Artifacts (IBTeC), a laboratory that conducts bond strength testing, there are some general acceptable ranges for bonding strength according to shoe type, for example, as follows:

[0087] (1) for protection, sports, children, military shoes: a minimum bonding strength of 6.0 N / mm is acceptable;

[0088] (2) for medium request shoes (daily use): a bonding strength of 4.5 N / mm is acceptable;

[0089] (3) for dress shoes; high heels; high fashion; light males: a bonding strength of 3.5 N / mm is acceptable; and

[0090] (4) for low demand shoes (e.g., sandals; slippers; homemade; child; and baby shoes): a bonding strength of 2.5 N / mm is acceptable.

[0091]

[0084] In embodiments, the foam article may comprise at least one of the following: a static compression set from 40% to 90%; a shrinkage from 0.1% to 3%; a hardness from 30 Shore A to 50 Shore A; and a rebound resilience from 35% to 65%.

[0092]

[0085] The desired static compression set may depend on the shoe type, but generally relatively lower values may be desired. In embodiments, the foam article may comprise a static compression set from 40% to 90%, from 40% to 80%, from 50% to 90%, from 50% to 80%, from 60% to 90%, from 60% to 80%, from 70% to 90%, or even from 70% to 80%, or any and all sub-ranges formed from any of these endpoints.

[0093]

[0086] The desired shrinkage may depend on the shoe type, but generally relatively lower values may be desired. In embodiments, the foam article may comprise a shrinkage from 0.1 % to 0.3%, from 0.1% to 2.5%, from 0.1% to 2%, from 0.1% to 1.5%, from 0.5 % to 0.3%, from 0.5% to 2.5%, from 0.5% to 2%, from 0.5% to 1.5%, from 1 % to 0.3%, from 1% to 2.5%, from 1% to 2%, or even from 1% to 1.5%, or any and all sub-ranges formed from any of these endpoints.

[0094]

[0087] The desired hardness may depend on the shoe type, but generally relatively lower Shore A values may be desired. In embodiments, the foam article may comprise a hardness from 30 Shore A to 50 Shore A, from 30 Shore A to 45 Shore A, from 30 Shore A to 40 Shore A, from 35 Shore A to 50 Shore A, from 35 Shore A to 45 Shore A, or even from 35 Shore A to 40 Shore A, or any and all sub-ranges formed from any of these endpoints.

[0095]

[0088] In embodiments, the foam article may comprise a rebound resilience from 35% to 65%, from 35% to 60%, from 35% to 55%, from 35% to 50%, from 40% to 65%, from 40% to 60%, from 40% to 55%, from 40% to 50%, from 45% to 65%, from 45% to 60%, from 45% to 55%, or even from 4% to 50%, or any and all sub-ranges formed from any of these endpoints.

[0096]

[0089] Expansion ratio may affect foam density and density may be related to many of the foam’s mechanical properties, such as hardness, compression set, and rebound. In embodiments, the foam article may comprise an expansion ratio from 140% to 170%, from 140% to 160%, from 150% to 170%, or even from 150% to 160%, or any and all sub-ranges formed from any of these endpoints.

[0097]

[0090] In embodiments, the foam article may comprise a density from 0.15 g / cm3to 0.30 g / cm3, from 0.15 g / cm3to 0.25 g / cm3, from 0.20 g / cm3to 0.30 g / cm3, or even from 0.20 g / cm3to 0.25 g / cm3, or any and all sub-ranges formed from any of these endpoints.

[0098]

[0091] In embodiments, the foam article may comprise a hardness from 30 Asker C to 60 Asker C, from 30 Asker C to 55 Asker C, from 30 Asker C to 50 Asker C, from 35 Asker C to 60 Asker C, from 35 Asker C to 55 Asker C, from 35 Asker C to 50 Asker C, from 40 Asker C to 60 Asker C, from 40 Asker C to 55 Asker C, or even from 40 Asker C to 50 Asker C, or any and all sub-ranges formed from any of these endpoints.

[0099]

[0092] The dynamic compression set may be used to quantify the fatigue resistance of a foam article. In general, a foam made from a foamable formulation of the present invention containing an elastomer, for example INFUSE™ 9500, may have the benefit of continuing to recover after several days, which may be understood as being more durable than a foam article made from a foamable composition without elastomer. For example, after someone runs using shoes having shoe midsoles containing elastomers, the midsoles recover at least part of its original thickness. The recovery may depend on the shoe type, but generally relatively high recovery may be desired. In embodiments, the foam article may have a recovery from 5% to 25%, from 5% to 20%, from 5% to 15%, from 10% to 25%, from 10% to 20%, from 10% to 15%, or any and all sub-ranges formed from any of these endpoints.

[0093] Process of Manufacturing Foam Article

[0100]

[0094] In embodiments, the process of manufacturing a foamable composition comprises mixing the foamable composition and forming a foam article from the foamable composition.

[0101]

[0095] The mixing of the foamable composition may comprise an injection molding process or a bun foam process. The components of the foamable composition, including virgin ethylene-vinyl acetate, ethylene-vinyl acetate recycled foam, elastomer, polarity modifier, a crosslinking agent, and a blowing agent, may be weighed and added to an internal mixer. The internal mixer may be a Branbury mixer of a thermos Haake mixer (available from Thermofisher) with tangential rotors to mix the foamable composition. A kneader mixer may also be used for mixing the foamable composition. The tangential rotors of the mixer provide the mixing and mixing also occurs between walls of the chamber and the tip of the rotor blades.

[0102]

[0096] The rotor speed of the internal mixer may be maintained at a rate that allows for mixing of the components without creating excessive shear heating, which may prematurely activate the crosslinking agent or the blowing agent in the foamable composition. In embodiments, the rotations per minute (rpm) may be from 50 rpm to 100 rpm to initially melt the resin, which may first be added to the mixer alone. Then, the rpm of the mixer may be lowered to about 50 rpm, and the remaining components are added to the mixer. The rpm and time of mixing may depend on the foamable composition. In embodiments, mixing of the foamable composition occurs at a temperature from 120 °C to 130 °C. The rotor speed of the internal mixer may be adjusted to maintain a desired temperature. In embodiments, the time of mixing may be from 10 minutes to 15 minutes.

[0103]

[0097] Once all the ingredients have been added to the mixer and thoroughly mixed, the batch may be dropped from the mixer into a catch pan with a non-stick liner (e.g., a polyethylene terephthalate (PET) film). The batch in the catch pan may then be quickly transferred to a roll mill station, where the batch is placed into a heated roll mill. The roll mill may be heated (e.g., from 90 °C to 105 °C) to keep the batch from solidifying during the finishing step of the batch, and to allow further mixing of any ingredients that may have transferred to the surface of the batch while exiting the internal mixer.

[0104]

[0098] In some embodiments, the batch may be passed once through the roll mill; and in other embodiments, the batch may be passed once through the roll mill, folded, and then re- passed through the roll mill 3 or 4 times to help disperse any ingredients that remain on the surface of the batch. Cooling the batch below the polymer solidification point (Tc) may be avoided because if the batch cools below Tc, that may cause the surface of the resulting formed “sheet” to become uneven. After from 1 min to 2 min of rolling a sample batch through the roll mill to form the sheet, the sheet may be removed from the roll mill and cooled to room temperature in preparation of foam molding.

[0105]

[0099] In some embodiments, the thickness of the sheet formed from the polyolefin composition may be sufficient to fill a molding chase by stacking one to three sheets in the molding chase. By minimizing the number of sheets stacked in the molding chase, the potential to create voids between the layers of sheets may be reduced. In one embodiment, a sample sheet stacked in the molding chase may be sandwiched in between two layers of release film. Then, the sample may be disposed in between two platens of the molding chase. The two platens may be closed and the sample compressed.

[0106]

[0100] To form a multi-layer foamed article, roll milled sheets of the different layers may be formed as described herein. The roll milled sheets may then be cut and placed inside a pre-heated bun foam mold or “chase.” In embodiments, the surface of the chase may be sprayed with a dry lubricant (e.g., a dry polytetrafluoroethane (PTFE) lubricant such as Fluoroflide) to avoid sticking of the foam to the chase during de-molding. The sample is then preheated, pressed, and cured to form the multi-layer foam article.

[0107]

[0101] TEST METHODS

[0108]

[0102] Density

[0109]

[0103] Density (for resins) was measured in accordance with ASTM D792 with results reported in g / cm3at 25 °C.

[0110]

[0104] Melt Index (MI)

[0111]

[0105] MI (for resins) was measured in accordance with ASTM D 1238, Condition 190 °C / 2.16 kg with results reported in grams per 10 minutes (g / 10 min).

[0112]

[0106] Expansion Ratio

[0113]

[0107] The general procedure for measuring the expansion ratio of a bun foam sample was carried out by measuring the initial length of a bun foam sample and the final length of the bun foam sample. The final length of the foam sample was measured after 2 hr of cooling at room temperature. Then, the ER of the bun foam sample was calculated using the following expression:

[0114] ((final length) - (initial length)) / (initial length).

[0115]

[0108] Foam samples that have similar expansion ratios were used for testing because foam samples having similar expansion ratios also have mechanical properties that are comparable to each other on the same basis.

[0116]

[0109] Foam Density (with skin)

[0117]

[0110] Hydrostatic density was measured per the method described in ISO 2781-18, method A. Foam samples to be tested were cut from the bun foams with skin. The bun foam template was weighed to the nearest 0.1 g, and the volume of the bun foam template was determined by measuring length, width, and thickness to the nearest 0.01 cm without removing the skin layer.

[0118] [Hl] Hardness (Asker C)

[0119]

[0112] An Asker C hardness measurement was done using a durometer device, which measures the indentation hardness of a foam material. The Hardness Asker C of a foam sample was measured using the method described in NBR 14455-15. In this testing method, a standardized indenter was pressed against and into a specimen (a foam sample with skin) to generate vertical penetration of the indenter into the specimen. The indenter was applied on the foam samples with skin during 3 s.

[0120]

[0113] Hardness (Shore A)

[0121]

[0114] The Hardness Shore A of a foam sample was determined using the method described in ASTM D2240-15. In this testing method, a standardized indenter was pressed against and into a specimen (a foam sample with skin) to generate vertical penetration of the indenter into the specimen. The indenter is applied on the foam sample with skin during 1 s.

[0122]

[0115] Static Compression Set

[0123]

[0116] The compression set of a foam sample was measured per the procedure described in ASTM D395-18, method B. Using this testing method, a compression of 25% was applied on the foam sample with skin for 4 hr at a temperature of 70 °C in an oven. The deformation (and consequently recovery) of the foam sample was measured 30 min after removing the sample from the oven.

[0117] Shrinkage

[0124]

[0118] The shrinkage of an expanded foam sample was evaluated according to the procedure established by German Institute PFI (Priif und Forschungsinstitut Pirmasens e.v.). The dimensions of three specimens of the foam samples with skin were measured before oven aging the samples for 4 hr at 70 °C. The dimensions of the specimens were measured again after oven aging the samples for 4 hr at 70 °C and after allowing the samples to cool for 1 hr at 23 °C.

[0125]

[0119] Dynamic Compression Set

[0126]

[0120] Dynamic compression set was measured per the method described inNBR 14739 / 10. The remaining deformation of the bun foam sample was measured immediately and 24 hr after 100,000 cycles of compression / release at 23 °C. The size of the specimen tested was 30 mm x 30 mm x 10 mm, the load on the specimen was 400 N (90 lb) maximum load, the disc used was 75 mm in diameter, and the disc had no inclination. “Recovery,” in percentage (%) is the difference of the deformation after 100k cycles and the deformation after 24 hr.

[0127]

[0121] Bond Strength

[0128]

[0122] Adhesion of the foam article to crystal flexible PVC sheets was determined using the procedure described in ABNT NBR 10456 / 2020. The bonding force was measured in N / mm in the longitudinal and transversal directions. The samples (foam specimens) were conditioned according to Condition A (23 °C ± 2 °C and 50 % ± 5 % relative humidity) for a minimum period of 24 hr, as described in ABNT NBR 10455:2021.

[0129]

[0123] The adhesion process described in the test procedure of ABNT NBR 10456 / 2020 includes the following steps:

[0130] (1) cleaning the foam specimen with special EVA solvent (90SO 270) using a clean cloth;

[0131] (2) leaving the foam specimen in an oven at 50 °C for 10 min;

[0132] (3) applying, with a clean cloth, the EVA primer (e.g., Kisafix KFPE70SUV) to the specimen;

[0133] (4) allowing the EVA primer to dry for 10 min;

[0134] (5) cleaning the crystal PVC sheets with acetone;

[0135] (6) allowing the sheets to dry for 3 min to 5 min; (7) applying the PU base adhesive (e.g., Kisafix PVC 180 ST) on EVA and crystal PVC

[0136] (8) leaving the adhesive to dry for 20 min;

[0137] (9) reactivating the set at a temperature of between 60 °C and 70 °C; and

[0138] (10) pressing the foam specimen for 15 s using rubber plates to assist in providing a compression of 703 kg / m2.

[0139]

[0124] Rebound Resilience

[0140]

[0125] A rebound test method refers to the determination of resilience of a material such as a foam, expressed as percentage resilience or rebound resilience of the material. A Schob Type pendulum rebound tester or device was used to generate the data for this test; and the procedure used for obtaining rebound measurements is described in DIN 53512. Using the pendulum rebound tester, rebound resilience was determined by a freely falling pendulum hammer that was dropped from a given height that impacts a test specimen and imparts to the test specimen a certain amount of energy. A portion of that energy was returned by the specimen to the pendulum and was measured by the extent to which the pendulum rebounds, whereby the restoring force was determined by gravity. Rebound resilience is the ratio of energy returned to energy applied. In the rebound resilience test, the resilience is established as the ratio of the height of rebound of a pendulum by the pendulum’s height of fall.

[0141]

[0126] The pendulum, from the pendulum’s initial horizontal position, impacted each specimen six times. The first three impacts served to mechanically condition the test specimen and the last three impacts served to establish the specimen’s rebound resilience. The median of the last three impact measurements was taken as the result of the specimen’s rebound resilience.

[0142]

[0127] EXAMPLES

[0143]

[0128] The following examples illustrate features of the present disclosure but are not intended to limit the scope of the disclosure. The following experiments analyzed the performance of embodiments of foamable compositions described herein.

[0144]

[0129] Materials used in Comparative Examples CE1-CE8 and Inventive Example IE1 are provided in Table 1 below.

[0130] Table 1

[0145] Ingredient Chemical Description Brand and Grade Source The Dow virgin ethylene18 wt.% vinyl acetate comonomer;

[0146] EL VAX™ 250A Chemical vinyl acetate d: 0.941 g / cm3; MI: 2.5 g / 10 min

[0147] Company ethylene-vinyl

[0148] PIR ethylene-vinyl acetate

[0149] acetate recycled - - d: 0.20 - 0.29 g / cm

[0150] foam3

[0151] ethylene-octene copolymer;

[0152] ENGAGE™ 8200

[0153] d: 0.870 g / cm3; MI: 5.0 g / 10 min

[0154] elastomer

[0155] olefin block copolymer;

[0156] INFUSE™ 9500

[0157] d: 0.877 g / cm3; MI: 0.50 g / 10 min The Dow ethylene-methyl acrylate Chemical Company copolymer; 30 wt.% acrylate ELVALOY™ AC polarity modifier

[0158] comonomer; 1330

[0159] d: 0.95 g / cm3; MI: 3 g / 10 min

[0160] crosslinking LUPEROX®

[0161] peroxide dicumyl Arkema agent DC40P-SP2

[0162] DONG JIN blowing agent azodicarbonamide UNICELL-D 300

[0163] SEMICHEM zinc oxide (ZnO) - Votorantim accelerator

[0164] zinc stearate (ZnSt) - Fisher Imerys filler calcium carbonate (CaCOs) - Carbonates

[0165]

[0166] filler / colorant titanium oxide (TiCE) - Auriquimica

[0167]

[0131] Preparation of foamable compositions

[0168]

[0132] A Banbury mixer with tangential rotors was used for mixing the foamable compositions. The following conditions / parameters were used: initial temperature of mixing was 80 °C, a capacity of 379 cm3, a filling factor of 70%, and a rotation of 60 rpm. Each composition was produced in 4 batches to have enough material to produce foam samples for all tests.

[0169]

[0133] A Cope mixer (available from Cope (Brazil)) was used to homogenize the aforementioned 4 batches of each composition as well as to produce thin sheets (having a thickness of ~2 mm). The following conditions / parameters were used: an initial temperature of 90 °C and a rotation of 14 rpm.

[0170]

[0134] Specimens of foam samples were produced from the comparative and foamable compositions using mold with dimensions of 100 mm x 100 mm x 10 mm. Each specimen was crosslinked by compression molding at a temperature of 170 °C (based on RPA results) for 10 min. A fast-opening press (available from FKL (Brazil)) was used for compression molding.

[0171]

[0135] The comparative and example foamable compositions and properties thereof are shown in Table 2.

[0172]

[0136] Table 2

[0173] CE1 CE2 CE3 CE4 CE5 ELVAX™ 250A 100 85 50 35 50 PIR ethylene-vinyl acetate - - - - - ENGAGE™ 8200 - 15 50 50 - INFUSE™ 9500 - - - - 50 ELVALOY™AC 1330 - - - 15 - LUPEROX® DC40P-SP2 1 1 1 1 1.25 UNICELL-D 300 2.5 2.5 2.3 2.1 2.3 zinc oxide (ZnO) 1 1 1 1 1 zinc stearate (ZnSt) 1 1 1 1 1 calcium carbonate (CaCOs) 5 5 5 5 5 titanium oxide (TiCU) 0.2 0.2 0.2 0.2 0.2 TOTAL 110.7 110.7 110.5 110.3 110.75 Expansion ratio (%) 155 160 160 156 157 Hardness (Shore A) 46.4 40.1 28.3 26.4 37.6 Hardness (Asker C) 59.3 51.5 42.8 41.3 48.7 Static compression set (%) 49.5 66.3 94.6 85.9 44.0 Density (g / cm3) 0.219 0.193 0.177 0.189 0.208 Shrinkage (%) 0.45 1.00 1.35 0.70 0.65 Thickness (mm) 13.6 14.2 14.8 14.0 13.9 Rebound resilience (%) 40.3 44.0 45.2 50.0 46.2 Dynamic compression set - deference after 100k cycles 23.4 40.9 57.2 56.2 36.4 (%)

[0174] Dynamic compression set - deference after 24 hr cycles 18.5 33.8 44.7 40.1 17.0 (%)

[0175] Recovery (%) 4.9 7.1 12.5 16.1 19.4

[0176]

[0177] Bond strength (N / mm) 2.8 2.4 1.5 1.6 0.1

[0137] Table 2 cont.

[0178] CE6 CE7 CE8 IE1 ELVAX™ 250A 80 65 65 50

[0179] PIR ethylene-vinyl acetate 20 20 20 20 ENGAGE™ 8200 - 15 - 15 INFUSE™ 9500 - - - - ELVALOY™AC 1330 - - 15 15 LUPEROX® DC40P-SP2 1 1 1 1 UNICELL-D 300 2.5 2.5 2.3 2.1

[0180] zinc oxide (ZnO) 1 1 1 1

[0181] zinc stearate (ZnSt) 1 1 1 1

[0182] calcium carbonate (CaCOs) 5 5 5 5

[0183] titanium oxide (TiCU) 0.2 0.2 0.2 0.2

[0184] TOTAL 110.7 110.7 110.5 110.3 Expansion ratio (%) 155 159 159 160 Hardness (Shore A) 46.1 38.9 39.9 35.1 Hardness (Asker C) 58.0 53.9 52.7 46.7

[0185] Static compression set (%) 60.2 57.8 52.9 71.9

[0186] Density (g / cm3) 0.227 0.210 0.215 0.196 Shrinkage (%) 1.35 0.95 1.50 1.15 Thickness (mm) 13.4 14.9 15.0 15.4 Rebound resilience (%) 43.0 43.0 41.8 45.0 Dynamic compression set - 15.2 33.8 22.9 33.3 deference after 100k cycles (%)

[0187] Dynamic compression set - 10.0 25.8 14.0 22.7 deference after 24 hr cycles (%)

[0188] Recovery (%) 5.2 8.0 8.9 10.6

[0189]

[0190] Bond strength (N / mm) 2.3 2.2 2.4 2.3

[0191]

[0138] As shown in Table 2, Inventive Example 1, a foamable composition including 20 phr PIR ethylene-vinyl acetate (ethylene-vinyl acetate recycled foam), exhibited a bond strength of 2.3 N / mm while also exhibiting a good balance of properties. As exemplified by Inventive Example 1, foamable compositions including greater than or equal to 15 phrethylene-vinyl acetate recycled foam as described herein may achieve a desired bond strength greater than or equal to 2.0 N / mm while also achieving other desired mechanical properties.

[0192]

[0139] While particular embodiments of the present disclosure have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the disclosure. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this disclosure.

Claims

CLAIMS1. A foamable composition comprising:virgin ethylene-vinyl acetate;greater than or equal to 15 phr ethylene-vinyl acetate recycled foam;elastomer, the elastomer comprising ethylene / alpha-olefin multi -block interpolymer, ethylene / alpha-olefm copolymer, or combinations thereof;polarity modifier, the polarity modifier comprising ethylene-alkyl (meth)acrylate copolymer;a crosslinking agent; anda blowing agent.

2. The foamable composition of claim 1 , wherein the virgin ethylene-vinyl acetate comprises a vinyl acetate level from 10 wt% to 35 wt%.

3. The foamable composition of claim 1, wherein the foamable composition comprises from 1 phr to 40 phr of the elastomer.

4. The foamable composition of claim 1, wherein the elastomer comprises a density from 0.850 g / cm3to 0.890 g / cm3and a melt index (MI) from 0.5 g / 10 min to 50 g / 10 min.

5. The foamable composition of claim 1, wherein the foamable composition comprises from 1 phr to 30 phr of the polarity modifier.

6. The foamable composition of claim 1, wherein the crosslinking agent comprises dicumyl peroxide.

7. The foamable composition of claim 1, wherein the blowing agent comprises azodicarbonamide.

8. The foamable composition of claim 1, wherein the foamable composition further comprises accelerator, filler, or combinations thereof.

9. The foamable composition of claim 8, wherein the accelerator comprises ZnO, ZnSt, or combinations thereof, and wherein the filler comprises CaCCh, TiCh, or combinations thereof.

10. A foam article comprising the foamable composition of claim 1.

11. The foam article of claim 10, wherein the foam article comprises at least one of the following:a static compression set from 40% to 90%;a shrinkage from 0.1% to 3%;a hardness from 30 Shore A to 50 Shore A; anda rebound resilience from 35% to 65%.

12. The foam article of claim 10, wherein the foam article is a shoe part.

13. The foam article of claim 10, wherein the foam article is a foam layer included in a multilayer structure, wherein the foam layer is bonded to a polar material layer.

14. The foam article of claim 13, wherein the foam article comprises a bond strength greater than or equal to 2.0 N / mm.

15. A process of manufacturing a foam article comprising:mixing a foamable composition at a temperature from 120 °C to 130 °C, the foamable composition comprising:virgin ethylene-vinyl acetate;greater than or equal to 15 phr ethylene-vinyl acetate recycled foam; elastomer, the elastomer comprising ethylene / alpha-olefin multi-block interpolymer, ethylene / alpha-olefin copolymer, or combinations thereof;polarity modifier, the polarity modifier comprising ethylene-alkyl (meth)acrylate copolymer;a crosslinking agent; anda blowing agent; andforming a foam article from the foamable composition, wherein the foam article comprises at least one of the following:a static compression set from 40% to 90%;a shrinkage from 0.1% to 3%;a hardness from 30 Shore A to 50 Shore A; anda rebound resilience from 35% to 65%.

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