Recyclable polymer laminates

Abstract

A recyclable laminate including (a) at least one first polymer film layer, (b) at least one second polymer film layer, and (c) one or more adhesives. The first polymer film layer includes a first polymer selected from a polyester polymer, a polyamide polymer, or a first polyolefin polymer and the second polymer film layer includes a second polyolefin polymer. The adhesive includes a block polymer of polyolefin and polyester polyol cured with a polyaliphatic isocyanate and having a structure in accordance with: where X, Y, X1, and Y1 are from 3 to 6; Z and Z1 are from 1 to 20; m, n, and h are from 1 to 12; and K is from 1 to 100. Further, the adhesive is disposed on the surface of at least one of the first or second polymer film layers for binding the first and second polymer film layers together.

Description

85730-WO-PCT / DOW 85730 WO RECYCLABLE POLYMER LAMINATES CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 604,474 filed November 30, 2023, the contents of which are incorporated in their entirety herein. TECHNICAL FIELD

[0002] The present invention is related to laminates having a recyclability property; and more specifically, the present invention is related to laminates, including a combination of a plurality of polymer film layers having different polymer types and an adhesive having a recyclability property. BACKGROUND

[0003] The use of plastic products, for example, packaging materials for the packaging industry, has significantly increased globally. Consequently, the increase in demand for plastic products has created a significant increase in plastic waste because after a plastic product has been used by the consumer the plastic product is discarded by the consumer. The plastic waste detrimentally impacts the environment and landscape throughout the world. To alleviate or reduce the plastic waste problem, manufacturers have attempted to produce a plastic product that can be recycled and reprocessed into other subsequent plastic products after the original plastic product has been used for its original purpose.

[0004] Further, sustainable packaging trends are driving the packaging industry towards recyclable, re-useable, and compostable plastic packaging. Flexible packaging, as one of most popular packaging materials, is commonly made from several layers of different types of plastic materials and foils or metalized films bonded together, with each layer serving a function in protecting the packaged contents. The most common application is for packaging food products, where flexible packaging preserves freshness and increases storage time. There are additional materials, such as inks, used for printing information on the packaging and the adhesives, which bond the multiple layers together to form the packaging materials. Because of the multiple layers of laminates, the different materials are incompatible when reprocessed directly by re-85730-WO-PCT / DOW 85730 WO compounding and recycling. Currently, in the flexible packaging industry, most flexible packaging materials are disposed of as trash, which results in more plastic waste in the environment. SUMMARY

[0005] Accordingly, there is an ongoing need for the development of plastic flexible packaging products which are fully and directly recyclable. To meet these needs, adhesives included in the laminate structure of flexible packing may be formulated to improve the mechanical properties of post-consumer recycled films or flexible packaging generated from recycling.

[0006] According to at least one embodiment of the present disclosure, a recyclable laminate comprises (a) at least one first polymer film layer, the first polymer film layer comprising a first polymer selected from a polyester polymer, a polyamide polymer, or a first polyolefin polymer; (b) at least one second polymer film layer, the second polymer film layer comprising a second polyolefin polymer; and (c) one or more adhesives, the adhesive comprising a block polymer of polyolefin and polyester polyol cured with a polyaliphatic isocyanate. Further, the block polymer of polyolefin and polyester polyol comprises a structure in accordance with:where X, Y, X1, and Y1 are from 3 to 6; Z and Z1 are from 1 to 20; m, n, and h are from 1 to 12; and K is from 1 to 100. Additionally, one or more adhesives are compatible with the at least one first polymer film layer and the at least one second polymer film layer and the layer of the one or more adhesives is disposed on the surface of at least one of the layers of the first polymer film layer and the second polymer film layer for binding the first polymer film layer and the second polymer film layer together.

[0007] According to at least one embodiment of the present disclosure, a packaging article made from the laminate of other embodiments is provided.85730-WO-PCT / DOW 85730 WO

[0008] These and other embodiments are described in more detail in the following Detailed Description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following figures in which:

[0010] FIGURE (FIG.) 1A is an image of phase separated morphology of Comparative Example 14;

[0011] FIG. 1B is an image of phase separated morphology of Inventive Example 10;

[0012] FIG. 1C is an image of phase separated morphology of Comparative Example 12;

[0013] FIG.1D is the image of phase separated morphology of Comparative Example 16;

[0014] Fig. 1E is the image of phase separated morphology of Comparative Example 17;

[0015] FIG. 2A is an image of phase separated morphology of Comparative Example 15;

[0016] FIG.2B is an image of phase separated morphology of Inventive Example 11; and

[0017] FIG. 2C is an image of phase separated morphology of Comparative Example 13. DETAILED DESCRIPTION

[0018] Specific embodiments of the present application will now be described. 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.

[0019] The term “recyclable” or “recyclability” herein, with reference to a first article such as a laminate, means mechanically recyclable or mechanical recyclability; and means the first article is mechanically re-processable to generate a second article having a desirable performance range. An example, and not to be limited thereby, of testing methods and guidelines for determining recyclability of a plastic article can be found in publication “Benchmark Polyethylene Film and Flexible Packaging Innovation Test Protocol, Film-B-01” (2018) and publication “PE85730-WO-PCT / DOW 85730 WO Film Standard Laboratory Processing Practices”, Document Number FPE-P-00 (2020) of The Association of Plastic Recyclers (APR).

[0020] The term “composition,” as used herein, refers to a mixture of materials which comprises the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0021] “Polymer” means a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The generic term polymer thus embraces the term homopolymer (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), and the term interpolymer as defined hereinafter. Trace amounts of impurities (for example, catalyst residues) may be incorporated into and / or within the polymer. A polymer may be a single polymer, a polymer blend or a polymer mixture, including mixtures of polymers that are formed in situ during polymerization.

[0022] The term “interpolymer,” as used herein, refers to polymers prepared by the polymerization of at least two different types of monomers. The generic term interpolymer thus includes copolymers (employed to refer to polymers prepared from two different types of monomers), and polymers prepared from more than two different types of monomers.

[0023] The terms “olefin-based polymer” or “polyolefin”, as used herein, refer to a polymer that comprises, in polymerized form, a majority amount of olefin monomer, for example ethylene or propylene or butylene (based on the weight of the polymer), and optionally may comprise one or more comonomers.

[0024] The term, “ethylene / a-olefin interpolymer,” as used herein, refers to an interpolymer that comprises, in polymerized form, a majority amount (e.g., greater than [>] 50 mole percent [mol %]) of units derived from ethylene monomer, and the remaining units derived from one or more a-olefins. Typical a-olefins used in forming ethylene / a-olefin interpolymers are C3-C10 alkenes.

[0025] The term, “ethylene / a-olefin copolymer,” as used herein, refers to a copolymer that comprises, in polymerized form, a majority amount (> 50 mol %) of ethylene monomer, and an α-olefin, as the only two monomer types.85730-WO-PCT / DOW 85730 WO

[0026] The term “a-olefin”, as used herein, refers to an alkene having a double bond at the primary or alpha (a) position.

[0027] “Polyethylene (PE)” or “ethylene-based polymer” shall mean polymers comprising a majority amount (> 50 mol %) of units which have been derived from ethylene monomer. This includes polyethylene homopolymers, ethylene / a-olefin interpolymers, and ethylene / a-olefin copolymers. Common forms of polyethylene known in the art include low density polyethylene (LDPE); linear low density polyethylene (LLDPE); ultra low density polyethylene (ULDPE); very low density polyethylene (VLDPE); medium density polyethylene (MDPE); high density polyethylene (HDPE); enhanced polyethylene; polyethylene elastomers; and polyethylene plastomers. These PE materials are generally known in the art; however, the following descriptions may be helpful in understanding the differences between some of these different PE resins. The term “LDPE” may also be referred to as “high pressure ethylene polymer” or “highly branched polyethylene” and is defined to mean that the polymer is partly or entirely homopolymerized or copolymerized in autoclave or tubular reactors at pressures above 14,500 pounds per square inch (psi) (100 megapascal [MPa]) with the use of free-radical initiators, such as peroxides (see for example U.S. Patent Nos. 8,916,667; 8,871,887; 8,822,601; 9,228,036; and 9,765,160). LDPE resins typically have a density in the range of 0.916 grams per cubic centimeter (g / cm3) to 0.935 g / cm3.

[0028] The term “LLDPE”, includes both resins made using the traditional Ziegler-Natta catalyst systems and chromium-based catalyst systems as well as single-site catalysts, including, but not limited to, bis-metallocene catalysts (sometimes referred to as “m-LLDPE”), constrained geometry catalysts (CGC), and molecular catalysts. Resins include linear, substantially linear, or heterogeneous polyethylene copolymers or homopolymers. LLDPEs contain less long chain branching than LDPEs and includes the substantially linear ethylene polymers which are further defined in U.S. Patent Nos. 5,272,236; 5,278,272; 5,582,923; and 5,733,155; the homogeneously branched linear ethylene polymer compositions such as those described in U.S. Patent No. 3,645,992; the heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Patent No.4,076,698; and / or blends thereof (such as those disclosed in U.S. Patent No. 3,914,342 or U.S. Patent No. 5,854,045). The LLDPEs can be made via gas- phase, solution-phase or slurry polymerization; or any combination thereof, using any type of reactor or reactor configuration known in the art.85730-WO-PCT / DOW 85730 WO

[0029] The term “MDPE” refers to polyethylenes having densities from 0.926 g / cm3to 0.940 g / cm3. “MDPE” is typically made using chromium or Ziegler-Natta catalysts or using single site catalysts including, but not limited to, bis-metallocene catalysts, constrained geometry catalysts, and molecular catalysts; and typically have a molecular weight distribution (“MWD”) > 2.5.

[0030] The term “HDPE” refers to polyethylenes having densities greater than 0.940 g / cm3and up to 0.970 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chrome catalysts or single-site catalysts including, but not limited to, bis-metallocene catalysts and constrained geometry catalysts.

[0031] The term “ULDPE” refers to polyethylenes having densities of 0.880 g / cm3to 0.912 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chrome catalysts, or single-site catalysts including, but not limited to, bis-metallocene catalysts and constrained geometry catalysts. "Polyethylene plastomers / elastomers" are substantially linear, or linear, ethylene / a-olefin copolymers containing homogeneous short-chain branching distributions comprising units derived from ethylene and units derived from at least one C3-C10 a-olefin comonomer, or at least one C4-C8 α-olefin comonomer, or at least one C6-C8 α-olefin comonomer. Polyethylene plastomers / elastomers have a density from 0.870 g / cm3, or 0.880 g / cm3, or 0.890 g / cm3to 0.900 g / cm3, or 0.902 g / cm3, or 0.904 g / cm3, or 0.909 g / cm3, or 0.910 g / cm3, or 0.917 g / cm3. Non-limiting examples of polyethylene plastomers / elastomers include AFFINITY™ plastomers and elastomers (available from The Dow Chemical Company), EXACT Plastomers (available from ExxonMobil Chemical), TAFMER™ (available from Mitsui Chemicals), NEXLENE™ (available from SK Chemicals Co.), and LUCENE™ (available from LG Chemical Ltd.); and mixtures thereof.

[0032] “Blend”, “polymer blend” and like terms mean a composition of two or more polymers. Such a blend may or may not be miscible. Such a blend may or may not be phase separated. Such a blend may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and any other method known in the art. Blends are not laminates, but one or more layers of a laminate may contain a blend. Such blends can be prepared as dry blends, formed in situ (e.g., in a reactor), melt blends, or using other techniques known to those of skill in the art.85730-WO-PCT / DOW 85730 WO

[0033] The terms “pre-consumer recycled polymer” and “post-industrial recycled polymer” (“PIR”) refer to polymers, including blends of polymers, recovered from pre-consumer material, as defined by ISO-14021. The generic term pre-consumer recycled polymer thus includes blends of polymers recovered from materials diverted from the waste stream during a manufacturing process. The generic term pre-consumer recycled polymer excludes the reutilization of materials, such as rework, regrind, or scrap, generated in a process and capable of being reclaimed within the same process that generated it.

[0034] The term “post-consumer recycled resin” or “post-consumer recycled polymer” (“PCR”), as used herein, refers to a polymeric material, including blends of polymers, recovered from materials previously used in a consumer or industry application, as defined by ISO-14021. The generic term post-consumer recycled resin thus includes blends of polymers recovered from materials generated by households or by commercial, industrial, and institutional facilities in their role as end-users of the material, which can no longer be used for its intended purpose. The generic term post-consumer recycled resin also includes blends of polymers recovered from returns of materials from the distribution chain. PCR resin is often collected from recycling programs and recycling plants. The PCR resin may include one or more of a polyethylene, a polypropylene, a polyester, a poly(vinyl chloride), a polystyrene, an acrylonitrile butadiene styrene, a polyamide, an ethylene vinyl alcohol, an ethylene vinyl acetate, or a poly-vinyl chloride. The PCR resin 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

[0035] PCR resin is distinct from virgin polymeric material. A virgin polymeric material 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 other than the polymer synthesis process or pelletization, like a typical PCR resin. 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 resin into formulations for commercial use.85730-WO-PCT / DOW 85730 WO

[0036] The terms “comprising,” “including,” “having,” and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether or not 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.

[0037] An objective of the present invention is to produce a directly recyclable laminate from original components for use in a first application; and then subsequently, after the laminate is used, the used the laminate can be reprocessed (i.e., the used laminate can be subjected to, for example, a recycling process), as a whole, to form a second article from the reprocessed laminate directly. The second article can then be used in another subsequent second application.

[0038] A further objective of the present invention is to process post-industrial recycled or post-consumer recycled laminates into recycled articles.

[0039] The first article includes a combination of: (a) at least one first polymer film layer, the first polymer film layer comprising a first polymer selected from a polyester polymer, a polyamide polymer, or a first polyolefin polymer; (b) at least one second polymer film layer, the second polymer film layer comprising a second polyolefin polymer such as polyethylene or polypropylene polymer; and (c) one or more adhesives, the adhesive comprising a block polymer of polyolefin and polyester polyol cured with a polyaliphatic isocyanate. It has been found that inclusion of the one or more adhesives according to the present disclosure imparts a recyclability property to the laminate; and thus, in some embodiments, the laminate is recyclable and can be used to produce the second article for various other applications. Specifically, different types of plastic materials in multilayer laminates, such as PET / LLDPE. PET / BOPP, metallized PET or PP / LLDPE, nylon / LLDPE, nylon / BOPP and further combinations are not directly compatible when melted. The incompatibility of these materials makes it challenging to directly mechanically recycle them to produce a recycled material that has useful physical properties. Further, the incompatibility typically results in micron- to millimeter-sized gels in the PCR resins and films generated from PCR and PIR materials generated from multilayer laminates. The laminates and85730-WO-PCT / DOW 85730 WO processes of the present disclosure address such undesirable gels with the inclusion of the adhesives in accordance with the present disclosure to effectively integrate the incompatible polymer layers of multilayer laminated from PCR and PIR materials during recycling to generate second articles for various other applications.

[0040] The first polymer film layer, component (a), useful for making the recyclable laminate of the present invention can include a polyester polymer, a polyamide polymer, or a first polyolefin polymer. In one or more embodiments, the first polyolefin polymer is at least one polyester polymer such as PET. In one or more embodiments, the first polyolefin polymer is at least one polyamide polymer such as nylon. In one or more embodiments, the first polyolefin polymer is at least one PE polymer. For example, the PE polymer, can include one or more of HDPE, LDPE, MDPE, LLDPE, and mixtures thereof. In another preferred embodiment, the first polymer film is polypropylene (PP), oriented PP (OPP), biaxially oriented PP (BOPP), or mixtures thereof. The first polyolefin film may be a monolayer or a multilayer film or may be an oriented film, oriented by machine direction orientation (MDO) or biaxial orientation processes.

[0041] The second polymer film layer, component (b), useful for making the recyclable laminate of the present invention can include a second polyolefin polymer. In one or more embodiments, the second polyolefin polymer is at least one PE polymer. For example, the PE polymer, can include one or more of HDPE, LDPE, MDPE, LLDPE, and mixtures thereof. The second polymer film may be a monolayer or a multilayer film or may be an oriented film, oriented by machine direction orientation (MDO) or biaxial orientation processes. In another preferred embodiment, the polyolefin is polypropylene (PP), oriented PP (OPP), biaxially oriented PP (BOPP), or mixtures thereof.

[0042] The one or more adhesives, component (c), useful for making the laminate of the present disclosure provides for integration of the various polymers forming the first polymer film layer and the second polymer film layer during recycling. The one or more adhesives provided as a component of the laminate comprises a block polymer of polyolefin and polyester polyol cured with a polyaliphatic isocyanate. The block polymer of polyolefin and polyester polyol comprises a structure in accordance with Formula I85730-WO-PCT / DOW 85730 WOFORMULA I Further, in accordance with Formula I, X, Y, X1, and Y1 are from 3 to 6; Z and Z1 are from 1 to 20; m, n, and h are from 1 to 12; and K is from 1 to 100. Further, the one or more adhesives are compatible with the at least one first polymer film layer and the at least one second polymer film layer with the layer of the one or more adhesives disposed on the surface of at least one of the layers of the first polymer film layer and the second polymer film layer for binding the first polymer film layer and the second polymer film layer together.

[0043] Having generally described the components of the recyclable laminate, embodiments of the laminate and the various components will be provided in further detail.

[0044] In one or more embodiments, the recyclable laminate is provided as a first article which can be used for producing a laminated packaging material that, in turn, can be recycled at the storefront for further processing. The multilayer laminate includes (a) at least one first polymer film layer, the first polymer film layer comprising a first polymer selected from a polyester polymer, a polyamide polymer, or a first polyolefin polymer;(b) at least one second polymer film layer, the second polymer film layer comprising a second polyolefin polymer; and(c) one or more adhesives, the adhesive comprising a block polymer of polyolefin and polyester polyol cured with a polyaliphatic isocyanate. The block polymer of polyolefin and polyester polyol includes a structure in accordance with Formula I as disclosed infra. Further, the one or more adhesives are compatible with the at least one first polymer film layer and the at least one second polymer film layer and the layer of the one or more adhesives is disposed on the surface of at least one of the layers of the first polymer film layer and the second polymer film layer for binding the first polymer film layer and the second polymer film layer together. One or more other optional film layer substrates can be added to the above laminate structure with the adhesive added in-between multiple layers to produce a multi-layer laminate structure comprising more than two layers, if desired.85730-WO-PCT / DOW 85730 WO

[0045] The first polymer film layer and the second polymer film layer, components (a) and (b), used for making the recyclable laminate of the present disclosure can include one or more polyolefins, polyesters, or polyamides. For example, in one or more embodiments, each of the first polymer film layer and the second polymer film layer, can include one or more polyolefin layers such as HDPE, LDPE, LLDPE, MDOPE, BOPE, PP, BOPP, and mixtures thereof. In one or more embodiments, the first polymer film layer may include one or more polyester layers such as poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(hexamethylene terephthalate) (PHT), and poly(propylene terephthalate) (PTT). Further, in one or more embodiments, the first polymer film layer may include one or more polyamides such as nylon.

[0046] In one or more embodiments, the second polymer film layer can include, for example, a polyethylene film web which is bonded to the first polymer film layer formed from PET through an adhesive. Similarly, in one or more embodiments, the second polymer film layer can include, for example, a polyethylene film web which is bonded to the first polymer film layer formed from nylon through an adhesive. It will be appreciated that a polyethylene film web was described for the second polymer film layer but a polypropylene film web could alternatively be utilized within the scope of the present disclosure.

[0047] In one or more embodiments, the first polymer film layer can include a multilayer film which is bonded to the second polymer film layer through an adhesive. Similarly, in one or more embodiments, the second polymer film layer can include a multilayer film which is bonded to the first polymer film layer through an adhesive.

[0048] The one or more adhesives for bonding the various layers of the laminate structure are selected to impart a recyclability property to the laminate structure. Specifically, as previously indicate, the different compositions of the various layers of the laminate structure frequently results in incompatibility between one or more layer components during recycling operations resulting in degradation of physical and / or mechanical properties. This phenomenon is typically addressed with the addition of a compatibilizer or other additive during the recycling operation. The adhesives of the present disclosure negate the need for the addition of a separate compatibilizer during recycling operations by providing the same or similar functionality as part of the adhesive itself. Accordingly, laminate structures in accordance with the present disclosure may be wholesale transferred to recycling operations without sorting, determination of the85730-WO-PCT / DOW 85730 WO laminate composition, or other processes which may be required when a separate compatibilizer is utilized.

[0049] According to the various embodiments, the adhesive comprises a block polymer of polyolefin and polyester polyol cured with a polyaliphatic isocyanate. The block polymer of polyolefin and polyester polyol comprises a structure in accordance with Formula I presented supra. Specifically, the block polymer may be a tri-block polymer with a polyester-polyolefin- polyester block configuration. In accordance with one or more embodiments, as presented in Formula I, X, Y, X1, and Y1are from 3 to 6 carbons in length. In one or more further embodiments, X, Y, X1, and Y1 are from 3 to 5 carbons in length. It is further noted that in accordance with various embodiments, X, Y, X1, and Y1 may represent the same structure or may represent different structures. For example X and X1may be the same and Y and Y1may be a different structure.

[0050] In accordance with one or more embodiments, as presented in Formula I, Z and Z1 are from 1 to 20. In various further embodiments, Z and Z1are from 1 to 18, from 1 to 15, from 1 to 12, from 1 to 10, from 2 to 10, or from 3 to 10. It is further noted that in accordance with various embodiments, Z and Z1 may represent the same structure or may represent different structures. For example, Z may be 6 and Z1 may be 8. It is noted that as Z and Z1 increase beyond the recited ranges the crystallinity of Formula I increases, thereby degrading performance.

[0051] In accordance with one or more embodiments, as presented in Formula I, m, n, and h are from 1 to 24. In various further embodiments, m, n, and h are from 1 to 20, from 1 to 15, from 1 to 10, from 2 to 10, from 2 to 8, or from 2 to 6. It is further noted that in accordance with various embodiments, m and h may represent the same structure or may represent different structures. For example, m may be 2 and h may be 3.

[0052] In accordance with one or more embodiments, as presented in Formula I, K is from 1 to 100. In various further embodiments, K is from 1 to 90, from 1 to 80, from 1 to 70, from 1 to 60, from 2 to 100, or from 2 to 80, or from 2 to 60.

[0053] Accordingly in one or more embodiments, the block polymer of polyolefin and polyester comprises a structure in accordance with Formula II presented infra.85730-WO-PCT / DOW 85730 WO

[0054] In one or more embodiments, the block polymer of polyolefin and polyester is the reaction product of a hydroxyl terminated hydrogenated polyolefin and one or more lactones. Specifically, the laminating adhesive may be prepared by grafting polyolefin polyol by polyetserification of lactone monomers to generate the block polymer material of polyolefin and polyester. The hydroxyl terminated hydrogenated polyolefin and the one or more lactones in one or more embodiments may be provided at a 1:5 to 5:1 weight ratio. In various further embodiments, the hydroxyl terminated hydrogenated polyolefin and the one or more lactones may be provided at a 2:1 to 4:1 weight ratio, 2.5:1 to 5:1 weight ratio, 2.5:1 to 4:1 weight ratio, or approximately 3:1 weight ratio.

[0055] Lactones are cyclic are cyclic esters of organic acids. It is a condensation product of an alcohol group and a carboxylic acid group in the same molecule of hydroxy containing aliphatic carbonic acid. In one or more embodiments, the lactones comprise one or more of caprolactone, delta-valerolactone, and delta-hexalactone. It is noted that caprolactone is alternatively known as oxepan-2-one, delta-valerolactone is alternatively known as oxan-2-one or penta-1,5-lactone, and delta-hexalactone is alternatively known as 6-methyloxan-2-one. In one or more embodiments, the lactone can be the general lactone structure illustrated in Formula II, where p can be from 3 to 10, or from 3 to 7, or from 3 to 5.85730-WO-PCT / DOW 85730 WO

[0056] Commercially available examples of the hydroxyl terminated hydrogenated polyolefin include Krasol® HLBH P 2000 (Total Energies, Courbevoie, France) which has a hydroyl number of 49.8 mgKOH / g and glass transition temperature (Tg) of –46℃ and Krasol® HLBH P 3000 (Total Energies, Courbevoie, France) which has a hydroxyl number of 31 mgKOH / g and Tg of -46℃.

[0057] In one or more embodiments, a catalyst is utilized to advance the reaction of the hydroxyl terminated hydrogenated polyolefin and the one or more lactones to form the block polymer of polyolefin and polyester. In one or more embodiments, the catalyst is tetra-isopropyl titanate (IV). In one or more further embodiments, the catalyst is titanium (IV) butoxide.

[0058] In one or more embodiments, the block polymer polyol of polyolefin-polyester may be prepared by transesterification of the polyolefin polyol with polylactone polyols.

[0059] As previously noted, the block polymer is further cured with a polyaliphatic isocyanate to provide unique adhesive performance and also improve the compatibility of PET and LLDPE, NYLON and LLDPE, and other polymer combinations after recycling and re- compounding. In one or more embodiments, the polyaliphatic isocyanate comprises a polyaliphatic diisocyanate. For example, the polyaliphatic isocyanate utilized to further cure the block polymer may be a polyhexamethylene diisocyanate which is commercially available as MOR FREE®C-33 (The Dow Chemical Company, Midland, MI) )or a poly (pentamethylene diisocyanate) which is commercially available as STABIOTMD-370N and STABIOTMD-376N (Mitsui Chemicals).

[0060] In one or more embodiments, the adhesive may be combined with one or more solvents to ease application and / or spreading of the adhesive during formation of the laminated structure. For example, the adhesive may comprise ethyl acetate or methyl ethyl ketone (MEK) added along with the polyaliphatic isocyanate or the polyols or both components to allow for the adhesive to be effectively applied during lamination. In various embodiments, the solvent may be added at 0 wt.%, 5, wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, or 60 wt.% based on the total weight of the adhesive at application. Accordingly, it will be appreciated that in certain embodiments the adhesive may be applied during lamination without the addition of any solvent. The amount of included solvent may be determined at least in part by the system or method utilized for application of the adhesive. For85730-WO-PCT / DOW 85730 WO example, hand application may desire a different amount of solvent than machine application and lamination.

[0061] The laminate structure of the present invention can include other optional layered substrates, component (d), in addition to the above component layers (a)-(c). For example, substrates such as EVOH, PVDC, OPA, and mixtures thereof can be laminated (bonded) to the above first polymer film layer and second polymer film, if desired. In further embodiments, a metallized layer may be laminated (bonded) to the above first polymer film layer and second polymer film, if desired. Alternatively, the first polymer film layer and / or the second polymer film may comprise a metallized layer, such as metallized PET.

[0062] In general, the articles and laminate of the present invention, prior to recycling, can be used in a wide range of applications including, for example, packaging applications for manufacturing various packaging materials and products. For example, the laminate can be used for bulk packaging of food grains / pulses, packaging of seeds, packaging of lentils and cereals, packaging of fertilizer, packaging of oilseed, packaging of sugar, packaging of salt, packaging of pharmaceuticals, packaging of other food stuff, and personal care items such as bath salts, detergent pods and the like. The film may also be used as a wrapper for baby wipes, feminine hygiene products, cereal bars, protein bars, cheese, and confectionary products. The recycled materials of the present invention can be used to produce further packaging materials as well as non-packaging materials.

[0063] One of the advantages of the articles and laminates in accordance with the present disclosure is that a used virgin article (first article) made from the laminate of the present disclosure can be reprocessed, that is, processed through a recycling process. After recycling, the recycled material from the previous virgin article can be used to make a subsequent recycled laminate, and in turn a recycled article (i.e., a second article), with properties and performances very close to the previous virgin article. One objective of the presently disclosed polymer structures is to produce a second article that performs as well as, or better than, the first article, that is the properties of the second article performs 100 % the same as, or greater than, the properties of the first article. At a minimum, the properties of the second article are maintained at a sufficient level of performance to provide a second article that is useful in another application.85730-WO-PCT / DOW 85730 WO

[0064] In a general embodiment, the process for producing a reprocessed second article from, for example, a first packaging article (that is, the virgin article) comprises the steps of: (A) providing a first packaging article made from the laminate of the present disclosure; (B) fragmenting the packaging article from step (A) to produce a plurality of fragments of a predetermined size; (C) pelletizing the plurality of fragments from step (B) to form a plurality of pellets of a predetermined size; and (D) processing the pellets from step (C) to form a reprocessed second article. Accordingly, the adhesive forming the laminate is formulated to allow for direct recycling without addition of additional or alternative additive or reprocessing aids such as compatibilizer.

[0065] In some embodiments, a third article can be produced from the reprocessed second article made by the above general processes. For example, the third article can be selected from the group consisting of: pellets, monolayer or multilayer films, multilayer laminates, and packaging materials or products.

[0066] EXAMPLES

[0067] The following examples are presented to further illustrate the present invention in detail but are not to be construed as limiting the scope of the claims. Unless otherwise indicated, all parts and percentages are by weight.

[0068] Various materials used in the Inventive Examples (Inv. Ex.) and the Comparative Examples (Comp. Ex.), which follow, are described in Table I. Table I - Raw Materials85730-WO-PCT / DOW 85730 WO

[0070] Inventive examples of polyester grafted polyolefin material (block polymer of polyolefin and polyester polyol) were synthesized to generate Inventive Example 1 and Inventive Example 2. The formulation for each example is provided in Table 2. After charging the given amount of Krasol HLBH P 2000 according to Table 2 in a 2 liter 4-neck round bottom flask, the material was heated to 105℃ under Nitrogen bubbling to dry the moisture in the polyol for 60 minutes. The flask was subsequently cooled to 40℃, a given amount of lactones according to Table 2 was added into the flask. Specifically, Captrolactone was added for Inventive Example 1 and a combination of Delta-Valerolactone and Delta-hexalactone was added for Inventive Example 2. Tetra-isopropyl Titanate catalyst, 3 drops, was added to the mixture. The reacting mixture was gradually heated to 185℃ within 2 hours under nitrogen protection, then the reaction was kept at temperature until the reaction mixture became a homogenous phase without phase separation. The reaction was monitored with FTIR to ensure the lactone monomer fully converted to polyester. Then the reactor was cooled to 60℃ and the reacted material was transferred into a 1 liter glass jar for characterization and adhesive performance testing. The generated polyester grafted polyolefin material was characterized with GPC, NMR, and MS spectra. The measured properties for Inventive Example 1 and Inventive Example 2 are provided in Table 3. Table 2 – Formulation of Inventive Examples 1 and 285730-WO-PCT / DOW 85730 WO Table 3 – Properties of Inventive Examples 1 and 2

[0071] Measurement of the properties disclosed in Table 3 were based on the following characterizations:

[0072] Hydroxyl Number (mgKOH / g)

[0073] To test hydroxyl number (OH#), samples are prepared and measured according to ASTM 4274 and reported in milligrams of potassium hydroxide per gram (mgKOH / g).

[0074] Gel Permeation Chromatography

[0075] Molecular weight of the Inventive Examples was measured by gel permeation chromatography (GPC). The samples were prepared for GPC analysis by dissolving approximately 20 mg of sample in 10 g of tetrahydrofuran (THF). GPC separations were carried out on a Waters Alliance HPLC system using an Agilent PLgel 5 µm particle size column (4 columns in 1 set, with pore size of 50, 100, 1000, 10000 Å). Calibration was completed using polystyrene standards from Agilent Technologies, PS EasiVials, prepared in THF. The reported molecular weight is the relative molecular weight based on the PS standard. Further, analysis conditions were as follows: Column temperature: 40℃; Eluent: Tetrahydrofuran, unstabilized; Flow rate: 1.0 mL / min; Injection volume: 100 µL; Sample concentration: 2.0 mg / mL; Analysis time: 45 min; and Detector: Waters Refractive Index detector and Waters 2489 UV / Vis Detector 254 nm.

[0076] Fourier Transform Infrared (FTIR) Spectra

[0077] Samples were scanned with Thermo Scientific™ Nicolet™ iS™5 FTIR Spectrometer with an iD7 ATR probe.85730-WO-PCT / DOW 85730 WO

[0078] Nuclear Magnetic Resonance (NMR) Spectroscopy

[0079] Both1H NMR and13C NMR spectra were collected from 400 MHz Bruker AVANCE 3 system.1H NMR was collected by dissolving approximately 150 mg of sample in approximately 650 mg of tetrachloroethane-d2 using a single-pulse experiment with a 10 µsec 90°-pulse, a 5 second acquisition time, and a 20 second recycle delay for 32 scans. Referenced chemical shifts to the residual solvent peaks at 5.96 (TCE).13C NMR was collected by dissolving approximately 450 mg of the grafted-polymer sample in approximately 2.7 g of TCE-d2 with 13 0.025M Cr(acac)3. Additionally a quantitative C spectrum was acquired using a 12.1 µsec 90°- pulse, a 1.4 sec acquisition time, a 6.4 second recycle delay, and 512 scans. Referenced chemical shifts to the residual solvent peak at 74.2 ppm. It is noted that NMR identified about 5 lactone units were attached at each side of the polyester block (Z and Z’ = approximately 5).

[0080] The viscosity profile of Inventive Example 2 at varying temperatures is provided in Table 4. The viscosity was measured by Brookfield viscometer DVII+ with Spindle #27 at 20 rpm. Table 4 – Viscosity of Inventive Example 2 at various temperatures

[0082] To test adhesion performance, adhesives in accordance with the present disclosure were prepared as Inventive Example 3 and Inventive Example 4. The inventive adhesives were formulated in accordance with Table 5 where Inventive Example 3 was formulated using Inventive Example 1 as the block polymer of polyolefin and polyester polyol and Inventive Example 4 was formulated using Inventive Example 2 as the block polymer of polyolefin and polyester polyol. Specifically, Inventive Example 3 was prepared by mixing Inventive Example 1 with MOR FREE®C-33 (polyaliphatic diisocyanate) and ethyl acetate as a solvent to reach a85730-WO-PCT / DOW 85730 WO targeted weight percentage of solid content of 45%. Mixing was completed with a FlackTek speed mixer at 1800 rpm for 1 mix cycle. Similarly, Inventive Example 4 was prepared by mixing a prewarmed 60℃ sample of Inventive Example 2 with MOR FREE®C-33 (polyaliphatic diisocyanate) by hand. In Table 5 it is noted that the equivalence ratios of the isocyanates to polyols containing a hydroxyl group are referred to as the NCO index. The cross-linking of theTable 5 – Formulation of Inventive Examples 1 and 2

[0083] Laminated structures were generated using the adhesive formulations of Inventive Examples 3 and 4. A laminated structure of PET (PET film) and LLDPE (GF-10) using Inventive Example 4 as the adhesive was prepared as Inventive Example 5. A laminated structure of Nylon (Nylon film) and LLDPE (GF-10) using Inventive Example 4 as the adhesive was prepared as Inventive Example 6. A laminated structure of PET (PET film) and LLDPE (GF-19) using Inventive Example 3 as the adhesive was prepared as Inventive Example 7.

[0084] Inventive Examples 5 and 6 were prepared with a Labocombi 3000 laminator at 100ft / min with inline corona treatment and 55℃ material temperature and 60℃ nip roll temperature.

[0085] Inventive Example 7 was prepared with hand lamination using a hot roll hand laminator with 66°C hot roll temperature, 40 psi pressure, and at 27 in / min speed.

[0086] The prepared laminates of Inventive Examples 5, 6, and 7 were cured at room temperature to test the bond strength at 1 to 2 days curing, 7 days curing, 14 days curing at in 45℃, and after Boil in bag condition of samples after the 7 days cure.85730-WO-PCT / DOW 85730 WO

[0087] Comparative Examples were also prepared using commercial adhesive products. Specifically, a laminated structure of PET (PET film) and LLDPE (GF-10) using ADCOTE™ 577 / CR 87-124 as the adhesive was prepared as Comparative Example 8. Further, a laminated structure of PET (PET film) and LLDPE (GF-19) using PACACEL L75-191 / CR 88-141 as the adhesive was prepared as Comparative Example 9. The lamination of Comparative Examples 8 and 9 was also completed with a Labocombi 3000 laminator at 100 ft / min with inline corona treatment and 55℃ material temperature and 60℃ nip roll temperature. The laminates of Comparative Examples 8 and 9 were cured at 25℃ with 50% humidity before performance testing according to adhesive technical data sheet requirements.

[0088] Measurement of T-peel bond strength was completed for each of Inventive Examples 5, 6, and 7 as well as Comparative Examples 8 and 9. The adhesion performance of Inventive Examples 5, 6, and 7 as well as Comparative Examples 8 and 9 is provided in Tables 7 and 8 according to ASTM D903 and ASTM D1876. T-peel bond strength was measured on a 1- inch strip of each sample at a rate of 10 inch / min on an Instron tensile tester with a 50 N loading cell. Three strips were tested for each laminate and high and mean strength were recorded together with the failure mode. In case of film tear and film stretch, the high value was reported and in other failure modes the average T-peel bond strength was reported. Typical failure modes include in a T-peel bond strength test include: AF- Adhesive failure (adhesive with primary; AT- Adhesive transfer (adhesive with secondary); AS- Adhesive split (cohesive failure of adhesive); FT- Film tear (destruct bond); and FS- Film stretch (destruct bond) with such convention used in Tables 7 and 8.

[0089] For the boil in bag testing of laminates, a cured laminate sample after 7 days of curing measuring 9 inch by 11 inch was folded over to form a double layer such that the PE film of one layer was in contact with the PE film of the other layer. The edges were then trimmed with a paper cutter to obtain a folded piece about 5 inch × 7 inch. The edges were then heat sealed to form a pouch with an interior size of 4 inch × 6 inch. The pouches were then filled 100 mL of a 1 / 1 / 1 sauce (blend of equal parts by weight of catsup, vinegar, and vegetable oil) through the open edge. After filling, the pouch was sealed in a manner that minimized the air entrapment inside of the pouch. The filled pouches were then carefully placed in boiling water and kept immersed in the water for 30 minutes. When completed, the extent of tunneling, delamination or leakage was compared with marked pre-existing flaws. The bags were then emptied and at least three 1-inch85730-WO-PCT / DOW 85730 WO strips were cut from the pouches and T-peel bond strength was measured as soon as possible according to the previously delineated protocols for T-peel bond strength testing.

[0090] For the heat seal bond strength testing, each of the tested laminates (Inventive Examples 5 and 6) after 7 days curing were heat sealed at 160oC, then the T-bond strength was measured on a 1-inch strip at a rate of 10 inch / min on an Instron tensile tester with 50 N loading cell and reported in the same manner as the above T-peel bond strength testing. Table 7 – Bond Strength Testing of Inventive Example 4 AdhesiveTable 8 – Bond Strength Testing of Inventive Example 3 Adhesive85730-WO-PCT / DOW 85730 WO

[0091] Films

[0092] To measure the compatibility of re-compounded materials formed from the laminated PET / / LLDPE and Nylon / / LLDPE laminates, further evaluation was completed. Specifically, the mechanical properties and phase separation of PET and PE or Nylon and PE was studied for Inventive Examples 5 and 6 re-compounded as well as additional Comparative Examples. Inventive Example 5 was re-compounded to generate Inventive Example 10. Inventive Example 6 was re-compounded to generate Inventive Example 11. A laminate formed from PET and LLDPE (GF-10) with commercially available compatibilizer ELVALOY™ PTW added at 6.6% wt.% was re-compounded to generate Comparative Example 12. A laminate formed from Nylon and LLDPE (GF-10) with commercially available compatibilizer FUSABOND™ E226 added at 6.6% wt.% was re-compounded to generate Comparative Example 13. A combination of PET and LLDPE (GF-10) without an adhesive or compatibilizer was recompounded to generate Comparative Example 14. A combination of Nylon and LLDPE (GF- 10) without an adhesive or compatibilizer was re-compounded to generate Comparative Example 15. Comparative Example 8 was re-compounded to generate comparative Example 16 and Comparative Example 9 was re-compounded to generate comparative Example 17

[0093] To prepare each of Inventive Examples 10 and 11 and Comparative Examples 12, 13, 14, 15, 16, and 17, the delineated laminated film plus more GF-10 to adjust the LLDPE mixing ratio was pre shredded and re-compounded in a Haake mixer. Specifically, a Haake Torque rheometer was employed to mix 200 grams of raw material for 10 minutes at 270 °C and 60 rpm to generate each sample. The compounded material was compressed to prepare a 3.2 mm thickness plaque for micro-tensile test and microphase separation observation. Specifically, compression molding of each sample was utilized in accordance with ASTM D4703. Molding temperature was 190°C with controlled cooling at 15°C / min.

[0094] A micro-tensile test was conducted to evaluate the mechanical property of the re- compounded materials by Instron tester machine. According to the ASTM D1708, the test is conducted at a test speed of 5 in / min. Table 9 provides the mechanical properties of the re- compounded inventive samples and the re-compounded comparison samples.85730-WO-PCT / DOW 85730 WO Table 9 – Mechanical Properties Based on Micro-Tensile Testing

[0095] The phase separation after re-compounding was also studied. Specifically, phase- separated morphology observation were conduction using Atomic Force Microscopy (AFM) and Confocal Laser Scanning Microscopy (CLSM). Accordingly, samples were polished under cryogenic conditions using a Leica UCT / FCS microtome operated at negative 120°C. Subsequently, topography and modulus images were captured at ambient temperature by using a Bruker Icon AFM system operated in PeakForce Tapping mode with the probe oscillating at 2 kHz. For samples with large domains CLSM (Keyence VK- X200) was used. The morphology measurements for each of Inventive Examples 10 and 11 and Comparative Examples 12, 13, 14, 15, 16 and 17 are provided in Table 10. The table includes diameter, area weighted diameter, neighbor distance and polydispersity index (PDI). Additionally, FIGS. 1A-1E provide phase morphology imaging for each of Comparative Example 14, Inventive Example 10, Comparative Example 12, 16 and 17 respectively representing the PET and LLDPE samples. Similarly, FIGS. 2A, 2B, and 2C provide phase morphology imaging for each of Comparative Example 15,85730-WO-PCT / DOW 85730 WO Inventive Example 11, and Comparative Example 13 respectively representing the Nylon and LLDPE samples. Table 10 – Phase-separated Morphology Measurements

[0096] Based on the teachings of Table 10 and FIGS. 1A, 1B, 1C, 1D, 1E, 2A, 2B, and 2C, it is demonstrated that the inventive adhesives reduced the PET phase separation particle size and enhanced their uniformity relative to PET / LLDPE without the adhesive. Such is indicative of improvement of compatibility of PET / LLDPE materials after re-compounding. Further, the enhanced uniformity is in line with comparative examples which utilized commercial compatibilizers. Similar results and improvement were demonstrated for Nylon / LLDPE.

[0097] Overall, the adhesive in accordance with the present disclosure improved the compatibility of the re-compounded PET / LLDPE film and Nylon / LLDPE film according to the mechanical property and the phase separation domains, which is comparable with the commercial compatibilizers for PET / LLDPE and Nylon / LLDPE, especially in view of the relative loading of the commercial compatibilizers. The adhesives in accordance with the present disclosure enable to direct recycling of flexible laminations of PET / LLDPE and NYLON / LLDPE to re-useful85730-WO-PCT / DOW 85730 WO plastic materials with good mechanical property, thereby reducing the plastic environmental impact.

[0098] It will be apparent that modifications and variations are possible without departing from the scope of the disclosure defined in the appended claims. More specifically, although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.

Claims

85730-WO-PCT / DOW 85730 WO CLAIMS 1. A recyclable laminate comprising: (a) at least one first polymer film layer, the first polymer film layer comprising a first polymer selected from a polyester polymer, a polyamide polymer, or a first polyolefin polymer; (b) at least one second polymer film layer, the second polymer film layer comprising a second polyolefin polymer; and (c) one or more adhesives, the adhesive comprising a block polymer of polyolefin and polyester polyol cured with a polyaliphatic isocyanate; and wherein: the block polymer of polyolefin and polyester polyol comprises a structure in accordance with:where X, Y, X1, and Y1 are from 3 to 6; Z and Z1 are from 1 to 20; m, n, and h are from 1 to 12; and K is from 1 to 100, the one or more adhesives are compatible with the at least one first polymer film layer and the at least one second polymer film layer, and the layer of the one or more adhesives is disposed on the surface of at least one of the layers of the first polymer film layer and the second polymer film layer for binding the first polymer film layer and the second polymer film layer together.

2. The laminate of claim 1, wherein the first polymer film layer comprises nylon.

3. The laminate of claim 1, wherein the first polymer film layer comprises polyethylene terephthalate.

4. The laminate of any of claims 1 through 3, wherein the second polymer film layer comprises linear low-density polyethylene.

5. The laminate of any of claim 1 through 4, wherein the block polymer of polyolefin and polyester comprises a structure in accordance with:85730-WO-PCT / DOW 85730 WO6. The laminate of any of claims 1 through 5, wherein the block polymer of polyolefin and polyester is the reaction product of a hydroxyl terminated hydrogenated polyolefin and one or more lactones.

7. The laminate of claim 6, wherein the hydroxyl terminated hydrogenated polyolefin and the one or more lactones are provided at a 2:1 to 5:1 weight ratio.

8. The laminate of claim 6 or 7, wherein the lactones comprise one or more of caprolactone, delta-valerolactone, and delta-hexalactone.

9. The laminate of any of claims 6 through 8, wherein the hydroxyl terminated hydrogenated polyolefin and the one or more lactones are combined in combination with tetra- isopropyl titanate.

10. The laminate of any of claims 1 through 9, wherein the polyaliphatic isocyanate comprises a polyaliphatic diisocyanate.

11. The laminate of any of claims 1 through 10, wherein the adhesive further comprises a solvent.

12. The laminate of claim 11, wherein the solvent comprises ethyl acetate or MEK.

13. The laminate of any of claims 1 through 12, wherein the first polymer film layer and the second polymer film layer comprise multilayer films.

14. A packaging article made from the laminate of any of claims 1 through 13.85730-WO-PCT / DOW 85730 WO 15. A process for producing a reprocessed second article from the packaging article of claim 14 comprising the steps of: (A) providing a packaging article of claim 14; (B) fragmenting the packaging article from step (A) to produce a plurality of fragments of a predetermined size; (C) pelletizing the plurality of fragments from step (B) to form a plurality of pellets of a predetermined size; and (D) processing the pellets from step (C) to form a reprocessed second article.

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