Coated film

Abstract

A coating film having improved optical properties and enhanced recyclability, the coating film comprising a combination of: (a) at least one film layer of recyclable polyolefin; and (b) at least one recyclable coating layer disposed on at least a portion of a surface on one side of the at least one film layer of recyclable polyolefin, such that the at least one coating layer provides the coating film with increased 60° gloss, reduced haze, improved clarity; and recyclability.

Description

Technical Field

[0001] This invention relates to coated films; and more specifically, to recyclable coated films comprising: (a) a polyethylene film substrate coated on one side with (b) at least one polyolefin dispersion coating. Coated films having advantageous recyclability can be used to manufacture articles such as flexible packaging. Background Technology

[0002] Many types of packaging developed to protect food, liquids, personal care products, and other products have been constructed with multi-layered laminated structures, such as two-layer PET / PE laminates and three-layer PET / nylon / PE laminates. Many packages include one or more transparent windows to showcase the product contained within and / or attract the attention of potential consumers. It is desirable that one or more windows on the packaging be as transparent and clear as possible to allow consumers to clearly identify the contents of the package through one or more windows. The transparency and clarity of common packaging materials such as polyethylene (PE) can be improved, for example, by altering properties of the packaging material (e.g., PE) such as the material's crystallinity. However, improvements in the transparency and clarity of packaging materials often result in a decrease in some mechanical properties of the packaging material, such as stiffness.

[0003] In addition, known two-component polyurethane-based coating compositions have been used with PE films to improve their gloss and transparency properties. However, the use of polyurethane-based coating compositions in packaging materials can cause (1) problems with the recyclability of PE due to gel formation in recycled materials; and (2) a significant reduction in the mechanical properties of the resulting film. For example, the transparency and clarity of PE films combined with known recycled coated PE films may be adversely affected compared to the transparency and clarity of pure (uncoated) PE films.

[0004] The aim is to provide new films and related materials for packaging that possess good optical properties, such as high gloss and low haze, and are easily recyclable.

[0005] U.S. Patent Application Publication Nos. US20160177073A1 and WO2000009594A1 disclose how to prepare polyethylene films by changing the composition of polyethylene. WO 2005 / 026275, US2005 / 010075, WO 2005 / 085331, EP2247445 B1, EP 3037472 B1, and EP3155052B1 disclose polyolefin dispersion compositions and the applications of such compositions. However, none of the above references disclose how to improve the optical properties of polyethylene-based films, such as gloss and haze.

[0006] WO2018064123A1 discloses coated films and packaging formed from such films. In one aspect, the coated film comprises: (a) a multilayer polymer film having first and second facial surfaces facing away from each other; and (b) a coating film layer on at least a portion of the first facial surface of the polymer film. The polymer film (component (a)) is at least one of polyethylene, polypropylene, polyethylene terephthalate, or polyamide. When measured using image analysis with atomic force microscopy, the first facial surface of the film has a root mean square surface roughness of at least 80 nm, and when measured using image analysis with atomic force microscopy, the second facial surface of the film has a root mean square surface roughness of less than (<) 80 nm. The coating film layer (component (b)) on at least a portion of the first facial surface is a polyurethane coating, and when measured in the coated portion of the first facial surface according to ASTM D1746 / 15, the coated film layer has a Zebedee clarity of at least 2 percent (%). WO2018064123A1 also discloses how to prepare polyethylene films with high gloss and high transparency having a polyurethane top coating. However, WO2018064123A1 does not teach the use of aqueous olefin copolymer dispersions as gloss-enhancing coatings. Summary of the Invention

[0007] This invention relates to recyclable coated films comprising: (a) a polyethylene film substrate coated on one side thereof with (b) at least one polyolefin dispersion coating. In addition to its mechanical recyclability, the coated films of this invention advantageously exhibit high gloss and high clarity (i.e., low haze) properties.

[0008] In some embodiments, the present invention includes a method for producing the above-described coated film.

[0009] In some embodiments, the present invention includes a first article made from the above-described coated film, such as granules, single-layer film, multi-layer film, single-layer laminate, multi-layer laminate, packaging material, molded product, etc.

[0010] In some embodiments, the invention includes a subsequent second article made from recycled material derived from any of the first articles described above.

[0011] Advantageously, the first article made from a coating film incorporating high gloss and low haze can undergo recycling processes according to current recycling guidelines in the packaging industry. For example, the coating polymer film structure formed by utilizing the coating dispersion of the present invention, comprising a recyclable polyethylene film (such as a full polyethylene (PE) or high-density polyethylene (HDPE) film) with a recyclable coating layer, provides an advantageous film structure that can be reprocessed to manufacture a new second article having substantially the same properties and performance as the first article. Detailed Implementation

[0012] In this article, “recyclable” and “recyclable” in relation to membrane products with waterborne olefin coatings refer to mechanical recyclability or recyclability; and mean that membrane products with waterborne olefin coatings are mechanically reprocessable to produce another subsequently recycled product with desired performance and desired characteristics.

[0013] In this article, "high gloss" of the film substrate refers to a gloss level exceeding 86 units.

[0014] In this article, “low haze” and “high clarity” for membrane substrates refer to coated membrane substrates having at least 30% lower total haze than uncoated membrane substrates.

[0015] In one broad embodiment, the present invention includes a recyclable coated film structure for producing packaging materials that can be recycled in stores. The recyclable coated film comprises a combination of: at least one heat-sealable recyclable polyolefin film substrate coated with a coating layer; and a coating layer disposed on at least a portion of a surface of one side of the polyolefin film layer.

[0016] According to one or more embodiments of the invention, the polyolefin film layer (component (a)) comprises, for example, a polyolefin film comprising a vinyl polymer; and the coating layer (component (b)) comprises, for example, a coating layer having improved optical properties such as high gloss, low haze, and high clarity; and it also has sufficient recyclability. Furthermore, the recyclable coating layer is advantageously compatible with the polyolefin layer.

[0017] Typically, the recyclable polymer membrane layer has an outer (or external or top) surface and an inner (or internal or bottom) surface; and the coating layer has an outer (or external or top) surface and an inner (or internal or bottom) surface. At least a portion of the inner surface of the coating layer is in contact with at least a portion of the outer surface of the polyolefin membrane layer. In a preferred embodiment, the outer surface of the coating layer forms the outer surface of the integral coated membrane structure (i.e., the polyolefin layer plus the coating layer). For example, in a general embodiment, the coated membrane of the present invention comprises (a) at least one polyolefin membrane layer, such as a polyethylene (PE) membrane; and (b) a high-gloss and low-haze coating layer bonded to the polyolefin membrane. If desired, one or more other optional membrane substrates may be added to the above membrane structure to produce a multilayer membrane structure.

[0018] In one or more embodiments, the polyolefin membrane web or layer (component (a)) used to prepare the coated membrane structure of the present invention is prepared from an olefin-based polymer. As used herein, the terms “olefin-based polymer,” “olefin-like polymer,” and “polyolefin” refer to a polymer containing a majority amount of an olefin monomer, such as ethylene or propylene (based on the polymer weight), in polymeric form, and optionally may contain one or more comonomers. The term “polymer” refers to a polymeric compound prepared by polymerizing monomers (whether of the same or different types). Thus, the general term polymer encompasses the term “homopolymer,” which is generally used to refer to a polymer prepared from only one type of monomer, and the term “copolymer,” which refers to a polymer prepared from two or more different monomers. The polyolefin membrane layer may comprise a membrane layer made from one polyolefin polymer or a membrane layer made from a blend of two or more different polyolefin polymers.

[0019] In one or more preferred embodiments, the polyolefin layer may comprise a vinyl polymer. As used herein, “polyethylene” or “vinyl polymer” should mean a polymer comprising greater than (>) 50 mol% of units derived from ethylene monomers. This includes vinyl homopolymers or copolymers as described above. Common forms of polyethylene known in the art include, but are not limited to: low-density polyethylene (LDPE); linear low-density polyethylene (LLDPE); ultra-low-density polyethylene (ULDPE); very low-density polyethylene (VLDPE); single-point catalytic linear low-density polyethylene, including linear and substantially linear low-density resins (m-LLDPE); medium-density polyethylene (MDPE); and high-density polyethylene (HDPE). For example, the polyolefin layer may comprise one or more polyolefin layers, such as HDPE, LDPE, LLDPE, MDO PE, BOPE, and mixtures thereof.

[0020] Additionally, as described herein, 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 partially or fully homopolymerized or copolymerized in an autoclave or tubular reactor at pressures above 14,500 psi (100 millipascals [MPa]) using a free radical initiator (such as a peroxide) (see, for example, U.S. Patent No. 4,599,392). The density of LDPE resin is typically in the range of 0.916 g / cm³ to 0.940 g / cm³.

[0021] As described herein, the term "LLDPE" can include resins prepared using Ziegler-Natta catalyst systems, as well as resins prepared using single-site catalysts, including but not limited to bismetallocene catalysts (sometimes referred to as "m-LLDPE"), phosphine imides, and catalysts with defined geometries; and resins prepared using post-metallocene, molecular catalysts, including but not limited to bis(biphenylphenoxy) catalysts (also known as polyaryloxy ether catalysts). LLDPEs include linear, substantially linear, or heterogeneous ethylene-based copolymers or homopolymers. LLDPE contains fewer long-chain branchings than LDPE and includes substantially linear ethylene polymers (as further defined in U.S. Patent Nos. 5,272,236; 5,278,272; 5,582,923; and 5,733,155); uniformly branched ethylene polymers (such as those described in U.S. Patent No. 3,645,992); non-uniformly branched ethylene polymers (such as those prepared according to the process disclosed in U.S. Patent No. 4,076,698); and blends thereof (such as those disclosed in U.S. Patent Nos. 3,914,342 or 5,854,045). LLDPE resins can be prepared via gas-phase, solution-phase, or slurry polymerization, or any combination thereof, using any type of reactor or reactor configuration known in the art.

[0022] Additionally, as described herein, the term "HDPE" refers to polyethylene having a density of about 0.940 g / cm³ or greater, which is typically prepared using Ziegler-Natta catalysts, chromium catalysts, or even metallocene catalysts. In one or more embodiments, the polyolefin membrane layer may be a multilayer membrane comprising an outer layer containing a vinyl polymer.

[0023] In some embodiments, the polyethylene polymer suitable for use in this invention may be commercially available, such as under the trade name AGILITY. TM(for example, AGILITY 1000, AGILITY 1001, and AGILITY 1021), INNATE TM ST 50, ELITE TM 5940, ELITE TM 5960, DOW TM LDPE 6211 and DOW TM LDPE 7511 is a polyethylene polymer, all of which are available from The Dow Chemical Company.

[0024] In one or more embodiments, the polyolefin membrane network or layer (component (a)) used to prepare the coated membrane structure of the present invention may comprise a single layer (monolayer) made of one or more polyolefins or olefin polymers; or the membrane structure may comprise a multilayer structure made of one or more polyolefin layers.

[0025] In other embodiments, the polyolefin film of the present invention may be a multilayer film comprising more than one layer. As described herein, "multilayer film" means any film having more than one layer. For example, a multilayer film may have two, three, four, five, or more layers. A multilayer film may be described having layers represented by letters to aid in describing the layers. For example, a two-layer film having two different polyolefin film layers may be represented as A / B; and a three-layer film having a core layer B and two outer layers A and C may be represented as A / B / C. Similarly, a structure having two core layers B and C and two outer layers A and D will be represented as A / B / C / D. In some embodiments, the polyolefin film may be a co-extruded film having an odd number of layers, such as 3 to 35, 3 to 11, or 3 to 7. For example, in some embodiments, the polyolefin film layer may be a three-layer multilayer film consisting of three polyethylene layers.

[0026] In a preferred embodiment, the polyolefin film layer may comprise an oriented monolayer or multilayer PE film manufactured using a longitudinal or biaxial orientation process, which is bonded to a second layer.

[0027] In another preferred embodiment, the polyolefin membrane layer may be a multilayer membrane comprising one or more HDPE, LLDPE and LDPE layers.

[0028] In another preferred embodiment, the polyolefin film layer may be a PP film or a biaxially oriented PP (BOPP) film layer.

[0029] The thickness of the polyolefin membrane used to form the polyolefin polymer membrane of the present invention can be, for example, from 12 micrometers (μm) to 125 μm in one embodiment, from 20 μm to 100 μm in another embodiment, and from 25 μm to 50 μm in yet another embodiment.

[0030] In one or more embodiments, the polyolefin film layer may have a thickness of less than or equal to (≤) 1 mm, such as ≤900 μm, ≤800 μm, ≤700 μm, ≤600 μm, ≤500 μm, ≤400 μm, ≤300 μm, or even ≤200 μm. The polyolefin film layer may have a thickness greater than or equal to (≥) 1 μm, ≥5 μm, ≥10 μm, ≥20 μm, ≥30 μm, ≥40 μm, or even ≥50 μm. As will be understood by those skilled in the art, in a multilayer film, the thicknesses of different layers may be the same or different; and the layer thickness may be selected based on the disclosure herein using techniques known to those skilled in the art.

[0031] The high-gloss and low-haze coating layer (component (b)) bonded to a polyolefin film to form a coated film structure is advantageously formed from a coating dispersion composition having recyclable properties. The coating dispersion composition imparts its recyclable properties to the coated film structure containing a recyclable coating layer made from the coating dispersion composition. Subsequently, when packaging articles are made from the recyclable film structure, the recyclable coating layer imparts acceptable recyclable properties to the articles made from the coated film (e.g., packaging articles).

[0032] In a broad embodiment, the coating dispersion composition that can be used in the present invention includes, for example, an aqueous coating composition comprising (A) at least one polymeric dispersant, such as ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, and mixtures thereof; and (B) at least one neutralizing agent.

[0033] According to various embodiments of the invention, the aqueous dispersion may contain a neutralizing agent, for example, causing the aqueous dispersion to have a pH in the range of 8 to 11. All individual values ​​and subranges of 8 to 11 are included herein and disclosed herein. For example, the aqueous dispersion may have a pH from a lower limit of 8, 8.1, 8.2, or 8.3 to an upper limit of 11, 10.9, 10.8, or 10.7. For example, the aqueous dispersion may have a pH of 8 to 11, 8.1 to 10.9, 8.2 to 10.8, or 8.3 to 10.7.

[0034] In one general embodiment, the neutralizing compound used in this invention has a boiling point below 140°C. Examples of neutralizing agents usable in this invention include, but are not limited to, hydroxides, carbonates, bicarbonates, amines, and combinations thereof. Examples of hydroxides usable in this invention include, but are not limited to, ammonium hydroxide, potassium hydroxide, lithium hydroxide, sodium hydroxide, and combinations thereof. Examples of carbonates usable in this invention include, but are not limited to, sodium carbonate, sodium bicarbonate, potassium carbonate, calcium carbonate, and combinations thereof. Examples of amines that can be used in this invention include, but are not limited to, monoethanolamine, diethanolamine, triethanolamine, ammonia, monomethylamine, dimethylamine, trimethylamine, 2-amino-2-methyl-1-propanol, triisopropanolamine, diisopropanolamine, N,N-dimethylethanolamine, mono-n-propylamine, dimethyl-n-propylamine, N-methanolamine, N-aminoethylethanolamine, N-methyldiethanolamine, monoisopropanolamine, N,N-dimethylpropanolamine, 2-amino-2-methyl-1-propanol, tris(hydroxymethyl)-aminomethane, N,N,N'N'-tetra(2-hydroxypropyl)ethylenediamine, 1,2-diaminopropane, 2-amino-2-hydroxymethyl-1,3-propanediol, N,N'-ethylenebis[bis(2-hydroxypropyl)amine]toluene-p-sulfonate, or cyclic amines such as morpholine, piperazine, piperidine, and combinations thereof.

[0035] Other components such as waxes, acid-functionalized waxes, and mixtures thereof may optionally be present in the dispersion composition. And optionally, a base resin, such as a polyolefin, is used in this invention, having a melt density (MI) >1 in one general embodiment and >20 MI in another embodiment; and a melt temperature <120°C in one general embodiment and <100°C in another embodiment. Examples of base resins that can be used in this invention include, but are not limited to, ENGAGE 8401, ENGAGE 8407, ELVAX 220W, and ELVAX 150W (available from Dow Chemical Company); and mixtures thereof.

[0036] The dispersant's MI is typically >60 in one embodiment and >250 in another embodiment; and the dispersant's MI is typically <1,500 in one embodiment and <600 in another embodiment. The dispersant's acid value is typically >80 in one embodiment and >120 in another embodiment; and the dispersant's acid value is typically <300. The base resin's melt temperature (Tm) is typically <120°C in one embodiment and <100°C in another embodiment; and the base resin's Tm is typically >40°C. The base resin's MI is typically >1 in one embodiment and >20 in another embodiment; and the base resin's MI is typically <1,200.

[0037] In some embodiments, examples of acid-functionalized waxes include, but are not limited to, maleic anhydride-modified waxes such as Licocene 431 (available from Clariant); acid-functionalized olefins such as Unicid 350 (available from Nucrea Solutions); fatty acids such as oleic acid; and combinations thereof. The acid in the dispersion formulation is neutralized by a base such as dimethylethanolamine or ammonia, which allows for the formation of an aqueous dispersion through the saponification of the acid present in the formulation.

[0038] The coating dispersion compositions of the present invention can be used to prepare films, which are then used to produce packaged products, such as for packaging fresh produce, frozen produce and common snacks.

[0039] The coating amount applied to the polyolefin layer can range from 0.8 grams per square meter (g / m²) in a typical embodiment. 2 The weight can be from 0.8 gsm to a maximum of 5 gsm, in another embodiment from 1 gsm to 3.5 gsm, and in yet another embodiment from 1.2 gsm to 3 gsm. Weights below 0.8 gsm can cause appearance problems and do not provide improved gloss or reduced haze. Any coating layer weight greater than 5 gsm may be difficult to dry and may increase haze.

[0040] In one general embodiment, the particle size of the particles present in the coating composition may be less than 1 μm.

[0041] According to one or more embodiments, the coating layer of the coated film has desired optical properties, such as gloss finish, reduced haze, and high transparency / clarity. As described herein, these optical properties are achieved during the fabrication of the coated film through the processing steps disclosed in this invention.

[0042] For example, in one or more embodiments, the coated film has a gloss level of at least 85 units at 60°. As described herein, the gloss level is measured using the ASTM D2457 standard. In another embodiment, the gloss level at 60° may be 85 to 105 units in one embodiment, 105 to 120 units in another embodiment, and 120 to 135 units in yet another embodiment.

[0043] As will be apparent from this disclosure, numerous advantages are present in the coated films and their preparation methods described in this invention. Specifically, film manufacturers can provide films with a gloss finish similar to conventional films using fewer layers. Furthermore, the same materials (i.e., polyolefin films and coating layers) can be used to form films with different optical finishes.

[0044] In some embodiments, the coating layer advantageously provides a film substrate with low or reduced haze characteristics. For example, the haze of the coated film may be ≤40% in one general embodiment; ≤30% in another embodiment; and ≤20% in yet another embodiment.

[0045] The thickness of the coating layer used to coat the polyolefin layer and form the recyclable coated membrane structure of the present invention can be, for example, from 1 μm to 5 μm in a general embodiment. Any coating layer thickness greater than 5 μm may be difficult to dry and may increase haze.

[0046] Once the coating layer is formed on the polyolefin layer, a coated film is produced. And as previously mentioned, the coating layer will provide a coated film with advantageous properties such as high gloss, low haze, and high clarity.

[0047] In other embodiments, the coating film exhibits sufficient recyclability to facilitate the recycling of a first article made from the coating film and the subsequent preparation of different second articles from the recycled material of the first article, such that the second article from the recycled material retains the same properties as the first article, or the second article does not exhibit at least 50% of the performance change compared to the first article.

[0048] In addition to the component layers (a) and (b) described above, the coated film structure of the present invention may also include other optional base layers, namely component (c). For example, in some embodiments, the polyolefin film structure may include a printed layer on the top surface of the polyolefin layer, wherein the printed layer may contact the coating layer; and thus, a multilayer film structure is formed, wherein the printed layer is disposed between the polyolefin layer and the coating layer. In such embodiments, the coating composition may be applied directly to the printed layer. The printed layer may be an ink layer displaying product details and other packaging information in various colors. The printed layer may be ≤15 μm in one embodiment, ≤10 μm in another embodiment, ≤5 μm in yet another embodiment, and even ≤2.5 μm in yet another embodiment.

[0049] If necessary, optional layers with specific functions, such as sealant layers, barrier layers, bonding layers, etc., can be added to the coated film structure.

[0050] In a broad embodiment, the recyclable coated film of the present invention is produced by applying the above-described coating dispersion composition to a surface on one side of a polyolefin membrane substrate to form a coating layer on the surface of the polyolefin membrane substrate. According to one or more embodiments, the coated film of the present invention can be prepared by a general method comprising the steps of: applying an uncured coating dispersion composition to at least a portion of the outer surface of a polyolefin membrane layer; and curing the uncured coating dispersion composition to form a coating layer on the polyolefin layer, thereby obtaining the coated film structure of the present invention. The application of the uncured coating composition allows the outer surface of the polyolefin layer to contact the inner surface of the coating layer.

[0051] For example, in one general embodiment, a method for producing a recyclable membrane structure includes the following steps: (I) providing (a) a polyolefin membrane substrate; and (b) a coating dispersion composition; (II) applying the coating dispersion composition to at least a portion of the surface of the polyolefin substrate to form a coating layer; and (III) curing the coating dispersion composition to form a cured coating layer on the top surface of the polyolefin substrate from step (II), thereby forming a coated film. As described herein, “applying” the coating dispersion composition to the polyolefin layer substrate may include contacting the coating composition with the polyolefin layer using any conventional means known in the art for applying coating compositions or formulations to a membrane substrate. For example, conventional film-forming equipment and processes, such as photogravure printing, flexographic printing, offset printing, Meyer rod drawdown, etc., may be used to apply the coating composition.

[0052] The coating dispersion composition is cured at a temperature below the melting temperature of the polyolefin film to avoid film stretching and deformation. Typically, in one embodiment, the coating is cured at a curing temperature of 15°C to 45°C, and in another embodiment, the coating is cured at a curing temperature of 20°C to 35°C.

[0053] In one or more embodiments, the uncured coating composition can be applied via a lamination process on a conventional laminating machine. For example, according to one or more embodiments, an uncured coating composition can be applied to a polyolefin film layer as it is moved longitudinally. That is, the polyolefin film layer can be conveyed longitudinally while the uncured coating composition is applied. As described herein, longitudinal refers to the direction in which the film flows onto or into a processing machine such as a laminating machine. The uncured coating composition can be deposited onto the polyolefin film layer using a smooth roller or a gravure roller, which can be selected at least in part by the viscosity of the uncured coating composition. The polyolefin film layer can begin in roll form, be unwound and conveyed longitudinally, wherein the uncured coating composition is applied to the polyolefin layer, and then the polyolefin layer is rewound into a roll.

[0054] According to the embodiments disclosed herein, after applying an uncured coating composition, the uncured coating composition can be cured to form a coating layer comprising a cured coating composition layer on the surface of a polyolefin layer. Curing can be “passive,” meaning it is carried out by allowing the uncured coating composition to stand under ambient conditions for a period of time. Alternatively, curing can be promoted by exposure to elevated temperatures, radiation, or other mechanisms that can cause curing to occur in the coating composition. In some embodiments, curing can be carried out while the polyolefin film layer and the uncured coating composition are laminated into a roll. After a period of time, the uncured coating composition solidifies and forms a roll of film comprising a coated film with a coating layer.

[0055] Because the coated film of the present invention exhibits excellent recyclability and improved optical properties, it can be used, for example, in packaging applications for manufacturing various packaging materials and products before recycling. For example, the coated film can be used for bulk packaging of food particles / beans, seed packaging, lentil and grain packaging, fertilizer packaging, oilseed packaging, sugar packaging, salt packaging, pharmaceutical packaging, and packaging of other food and personal care items such as bath salts and detergent pods. The coated film can also be used as a wrapper for baby wipes, feminine hygiene products, cereal bars, protein bars, cheese, and confectionery products. Furthermore, other advantageous features and applications of the recyclable film when used in packaging articles include, for example, resistance to harsh weather conditions, high tensile strength, robust drop test performance, excellent optical appearance, and spill resistance.

[0056] One advantage of this invention is that used (post-consumer) original (or first) articles made from the coated film of this invention can be processed through a recycling process. After recycling, the recycled material from the previous original first article can be used to prepare a subsequent recycled film, and the subsequent recycled film can then be used to prepare a recycled (or second) article. The resulting subsequent recycled film can be advantageously used to manufacture a subsequently recycled second article having characteristics and properties very close to the previous original first article. For example, a novel monolayer recycled film structure made from recycled material derived from a previous original first article may exhibit a performance change of <50% relative to a control original film that has been reprocessed similarly without any recycled material. In some embodiments, the novel monolayer film structure may exhibit a performance change ranging from 0% to <50% in one embodiment, from 0.01% to <40% in another embodiment, and from 0.1% to <30% in yet another embodiment.

[0057] In some embodiments, the novel monolayer membrane structure may exhibit performance variations of <50% in one embodiment, <25% in another embodiment, and <10% in yet another embodiment. In some embodiments, the novel monolayer membrane structure may exhibit performance variations ranging from 0% to <50% in one embodiment, from 0.01% to <50% in another embodiment, and from 0.1% to <50% in yet another embodiment. In some embodiments, the novel monolayer membrane structure may exhibit performance variations ranging from 0% to <25% in one embodiment, from 0.01% to <25% in another embodiment, and from 0.1% to <25% in yet another embodiment. In some embodiments, the novel monolayer membrane structure may exhibit performance variations ranging from 0% to <10% in one embodiment, from 0.01% to <10% in another embodiment, and from 0.1% to <10% in yet another embodiment. The recyclable membrane structure and its recyclability performance meet the recyclability guidelines of the Association of Plastic Recyclers.

[0058] Example

[0059] The following inventive embodiments (Inv.Ex.) and comparative embodiments (Comp.Ex.) (collectively, “Examples”) are given herein to further illustrate the features of the invention, but are not intended to be construed, explicitly or implicitly, as limiting the scope of the claims. Inventive embodiments of the invention are indicated by Arabic numerals, and comparative embodiments by alphabetical letters. The following experiments analyze the performance of embodiments of the compositions described herein. Unless otherwise indicated, all parts and percentages are by weight based on total weight.

[0060] The various materials used in the following examples are described in Tables I-III.

[0061] Table I - Raw Materials

[0062]

[0063]

[0064] General procedure for preparing component A of polyurethane coatings

[0065] The components and their corresponding amounts described in Table II are used for component A in the preparation of the polyurethane coating of the present invention.

[0066] Table II - Composition of Component A in Polyurethane Coatings

[0067]

[0068] To prepare component A using the ingredients described in Table II, wax esters and trimethylolpropane were loaded into the reactor, followed by ethyl acetate. MDI was vacuum-loaded into the reactor and then washed with the remaining ethyl acetate. The resulting batch was maintained at 70°C for 3 hours (hr). The batch was then cooled to 55°C. Corn oil was vacuum-loaded into the reactor. Cyclohexane was then added to the reactor, and the contents were maintained at 45°C and stirred for 45 minutes (min) until the contents became clear. Benzoyl chloride was then vacuum-loaded into the reactor, and the contents were stirred for 15 minutes. The resulting reactant component A was then packaged for later use.

[0069] General procedure for preparing component B of polyurethane coatings

[0070] The components and their corresponding amounts described in Table III are used to prepare Group B of the polyurethane coatings of the present invention.

[0071] Table III - Composition of Component B in Polyurethane Coatings

[0072]

[0073] To prepare reactant component B, TIPA was first melted. Voranol 220-260 was vacuum-loaded into the reactor. Molten TIPA was then vacuum-loaded into the reactor, followed by Voranol 220-110N. The vacuum line was flushed with ethyl acetate, and the reactor contents were stirred at 75 rpm. Ethyl acetate was vacuum-loaded into the reactor. The reactor contents were cooled via a cooling jacket. After cooling, TDI was loaded into the reactor, and the vacuum line was flushed with ethyl acetate. Due to the exothermic nature of the reaction, the reactor contents were cooled to 75°C. The temperature in the reactor was maintained at 75°C with stirring for 4 hours. The reactor contents were then cooled to 60°C. After cooling to 60°C, a mixture of defoamer, cellulose acetate butyrate, Modaflow, and the remaining ethyl acetate was vacuum-loaded into the reactor. The reactor contents were then stirred at 60°C for 60 minutes. The reactor was then cooled to 50°C. The resulting reactant component B was packaged for later use.

[0074] Examples 1-5 of this invention: Polyolefin dispersions

[0075] General procedures for preparing polyolefin dispersions

[0076] The aqueous dispersions of Examples 1 to 5 of the present invention having the compositions described in Table IV below were prepared using the following methods: (1) the raw materials described in Table I above; (2) the conditions described in Table IV; and (3) the following general procedures:

[0077] Components 1 to 3 described in Table IV are fed into a 25 mm diameter twin-screw extruder using a rate-controlled feeder; the feed rate is indicated in "g / min" as shown in Table IV. Components 1 to 3 are passed forward through the extruder and melted to form a liquid molten material.

[0078] The extruder temperature profile is raised to the temperatures described in Table IV. Water and a volatile alkali and / or neutralizing agent (dimethylethanolamine (DMEA) or 28% ammonia (NH4OH) in all Examples 1 to 5 of this invention) are mixed together and fed into the extruder at the rate described in Table IV to neutralize at the initial water introduction point. Then, dilution water is fed into the extruder at the rate described in Table IV. The extruder temperature profile is cooled back to below 100°C near the end of the extruder. The extruder speeds used, in rpm, are also described in Table II. At the extruder outlet, the pressure inside the extruder barrel is regulated using a back pressure regulator to a pressure suitable for reducing steam formation (typically, for example, this pressure is 2 MPa to 4 MPa).

[0079] Each aqueous dispersion discharged from the extruder was filtered through a 200-micron (μm) filter. The resulting filtered aqueous dispersions had a solids content measured as a weight percentage (wt%).

[0080] Table IV – Polyolefin Dispersions

[0081]

[0082]

[0083] Examples 6-19 of the present invention and Comparative Example AF: Coated film

[0084] Membrane structure

[0085] The film structures coated with the dispersions of Examples 1-5 of the present invention described in Table IV are described in Table V.

[0086] Table V - Membrane Structure

[0087]

[0088] General procedure for preparing coated PE substrate samples

[0089] Coated PE substrate samples for testing were prepared by manually coating the wet polyolefin coating dispersions (hereinafter referred to as POD1-POD5) of Examples 1-5 of the present invention described in Table IV above. POD1 to POD5 were manually coated onto one side of the surface of the PE substrates (hereinafter referred to as PE1, PE2, and PE3) described in Table V above. For example, coated polyethylene film substrate samples were prepared by manually coating a polyolefin dispersion such as POD1 onto a polyethylene substrate such as PE1 (a bilayer film structure of INNATE ST 50 and AFFINITY PL1880G with a thickness of 50 μm). The wet coating layer was applied to the PE substrate sample by hand using a K-controlled coating machine #2 doctor blade. The resulting coated substrate sample was then dried in a 70°C convection oven for 2 minutes to remove water present in the dispersion. The coating layer amount was approximately 2.9 g / m². 2 The coated PE film substrate samples of Examples 6–19 and Comparative Examples B, D, and F are described in Tables VI–VIII. Tables VI–VIII also describe the pure (uncoated) polyethylene films of Comparative Examples A, C, and E.

[0090] General procedures for testing coated PE substrate samples

[0091] The optical properties, including gloss and haze, of the coated PE film substrate samples of Examples 6–19 and Comparative Examples B, D, and F prepared as described above were tested. The gloss of the cured coated substrate samples at 60° was tested based on ASTM D2457. The total haze of the cured coated substrate samples was tested based on ASTM D1003. The test results for the coated PE film substrate samples are described in Tables VI–VIII. From the data in Tables VI–VIII, it can be determined that the coated polyethylene film samples of the present invention exhibit high gloss and low haze compared to comparative pure (i.e., uncoated) polyethylene film samples.

[0092] Table VI

[0093] <![CDATA[ Example number ]]> <![CDATA[ Material Description ]]> <![CDATA[ 60° gloss ]]> <![CDATA[ Haze (total) ]]> Comparative Example A Pure PE 1 99.18 12.5 Comparative Example B Polyurethane coated PE1 130.8 7.67 Embodiment 6 of the present invention POD2 coated PE1 114.8 8.35 Embodiment 7 of the present invention POD3 coated PE1 130 6.46 Embodiment 8 of the present invention POD4 coated PE 1 126 7.17 Embodiment 9 of the present invention POD5 coated PE 1 129.2 6.6

[0094] Table VII

[0095] <![CDATA[ Example number ]]> <![CDATA[ Material Description ]]> <![CDATA[ 60° gloss ]]> <![CDATA[ Haze (total) ]]> Comparative Example C Pure PE 2 78.92 20.56 Comparative Example D Polyurethane-coated PE 2 133.2 9.29 Embodiment 10 of the present invention POD1 coated PE 2 95.98 10.68 Embodiment 11 of the present invention POD2 coated PE 2 118.8 10.34 Embodiment 12 of the present invention POD3 coated PE 2 126.8 9.21 Embodiment 13 of the present invention POD4 coated PE 2 128.2 9.6 Embodiment 14 of the present invention POD5 coated PE 2 128 8.84

[0096] Table VIII

[0097] <![CDATA[ Example number ]]> <![CDATA[ Material Description ]]> <![CDATA[ 60° gloss ]]> <![CDATA[ Haze (total) ]]> Comparative Example E Pure PE 3 79.14 40.78 Comparative Example F Polyurethane coated PE 3 124.2 17.3 Embodiment 15 of the present invention POD1 coated PE 3 92.46 18.08 Embodiment 16 of the present invention POD2 coated PE 3 108.2 17.92 Embodiment 17 of the present invention POD3 coated PE 3 113.8 17.52 Embodiment 18 of the present invention POD4 coated PE 3 110.8 16.7 Embodiment 19 of the present invention POD5 coated PE 3 116.6 16.62

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

[0099] As will be apparent from the claims, the use of the singular also includes the possibility of the plural. For example, reference to a coating layer also implicitly includes reference to at least one coating layer.

[0100] It should be noted that one or more of the appended claims utilize the term "wherein" as a transitional expression. For the purposes of defining the invention, it should be noted that the term "wherein" is introduced in the claims as an open transitional phrase used to introduce a series of features of the structure and should be interpreted in the same manner as the more commonly used open-ended leading term "comprising".

Claims

1. A second article made from recycled material from a first article, wherein the first article is a coating film having improved optical properties and enhanced recyclability, the coating film comprising a combination of the following: (a) a multilayer recyclable polyolefin film which is a bi-layer film having a coated polyethylene film layer (A) and a non-coated polyethylene film layer (B); wherein, The density of the polyethylene film layer (A) is greater than that of the polyethylene film layer (B); and (b) at least one coating layer, wherein the at least one coating layer is made of a coating dispersion composition comprising: (A) At least one polymeric dispersant comprising an ethylene (meth)acrylic acid copolymer; (B) At least one neutralizing compound with a boiling point below 140°C, selected from the group consisting of dimethylethanolamine and ammonia; (C) Optionally, at least one polyolefin base resin with a melt index greater than 1; and (D) Optionally, at least one wax compound; The coated film has a gloss of at least 85 units at 60° as measured by ASTM D2457; the coated film has a haze of 30% lower than that of the uncoated film as measured by ASTM D1003; the at least one coating layer has a recyclability property with a performance change of less than 50% compared to a film without the coating layer; and the at least one coating layer is disposed on at least a portion of the surface of one side of the at least one film layer of the recyclable polyolefin.

2. A packaging article made of a coated film according to claim 1.

3. A recycled article, said recycled article being made from the coating film according to claim 1.

4. A method for producing a second article made from recycled materials from a first article, The first article is a coated film with improved optical properties and recyclability, and the method includes bringing the following items into contact: (a) a multilayer recyclable polyolefin film that is a dual layer film having a first coated polyethylene film layer and a second uncoated polyethylene film layer; wherein, The first coated polyethylene film layer and the second uncoated polyethylene film layer each contain different types of polyethylene; and the density of the coated polyethylene film layer is higher than that of the uncoated polyethylene film layer; and (b) at least one coating layer, wherein the at least one coating layer is made of a coating dispersion composition comprising: (A) At least one polymeric dispersant comprising an ethylene (meth)acrylic acid copolymer; (B) At least one neutralizing compound with a boiling point below 140°C, selected from the group consisting of dimethylethanolamine and ammonia; (C) Optionally, at least one polyolefin base resin with a melt index greater than 1; and (D) Optionally, at least one wax compound; The at least one coating layer has a 60° gloss of at least 85 units as measured according to ASTM D2457; the coated film has a haze of 30 percent lower than that of the uncoated film as measured according to ASTM D1003; the at least one coating layer has a recyclability property with a performance change of less than 50 percent compared to a film without the coating layer; and the at least one coating layer is disposed on at least a portion of the surface of one side of the at least one film layer of the recyclable polyolefin.

5. A method for producing recycled membrane products, the method comprising the following steps: (i) Providing a first post-consumption packaged article as claimed in claim 2; (ii) The first packaged article from step (i) is broken into a plurality of fragments of a predetermined size; (iii) The plurality of fragments from step (ii) are granulated to form a plurality of granules of a predetermined size; as well as (iv) Process the granules from step (iii) to form different recycled second membrane articles.

6. A recycled membrane product, said recycled membrane product being produced by the method according to claim 5.

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