Recycled polymer formulations

Abstract

Disclosed herein are a polyethylene composition including high density recycled polyethylene compositions, and a film including the same. The polyethylene composition according to embodiments disclosed herein includes a high density recycled polyethylene composition, a LDPE, and an ethylene-based elastomer. The combination of polymers, when used in a film can allow for the inclusion of recycled polyethylene in films without loss of desirable properties and with improved, maintained, or desirable film properties such as toughness and low gel content.

Description

[0001] RECYCLED POLYMER FORMULATIONS

[0002] FIELD

[0003] Embodiments described herein relate to a polyethylene composition and a multilayer film comprising a high density recycled polyethylene composition.

[0004] INTRODUCTION

[0005] A challenge faced by the polymer industry is the environmental impact of its products, especially the accumulation of plastic waste in landfills and oceans. For example, plastic polymer waste poses a threat to ecosystems. There is a growing demand from society and regulators for more sustainable solutions that reduce plastic polymer waste with an increase in plastic recycling and incorporation of recycled polymers. This demand centers on the idea that recycling plastic and incorporating polymers back into products can save resources and energy.

[0006] Recycling polymers is not an easy task. Recycling polymers and incorporating post recycled polymers into new products is likewise not an easy task. Waste is often contaminated, degraded, mixed, or incompatible with other types of materials. Moreover, post recycled polymers have different properties such as mechanical and optical properties than virgin polymers, which limits their applications and market value. Therefore, there is a need for innovative technologies that can enhance the compatibility and blendability of recycled polymers and permit the use of recycled polymers without compromising performance.

[0007] One application of recycled polymers is in the production of films. Accordingly, it is necessary to find ways to provide films that retain a balance of properties and incorporate recycled polymers.

[0008] SUMMARY

[0009] Embodiments of the disclosure can help solve the above problems and others in providing a polyethylene composition that can incorporate a high density recycled polyethylene composition and can be incorporated into films that show a reduction of gels along with maintained or improved mechanical properties.

[0010] In a first aspect, a polyethylene composition is disclosed. The polyethylene composition comprises (a) a high density recycled polyethylene composition having a density greater than 0.940g / cc and a melt index (12) of less than 2.50 g / 10 min, according to ASTM D1238 (2.16 kg and 190°C); (b) a low density polyethylene (LDPE) having a density from 0.910 to 0.930 g / cc; and (c) an ethylene-based elastomer having a density of less than 0.900 g / cc; and wherein the polyethylene composition comprises at least 30 wt.% of the high density recycled polyethylene composition, at least 5 wt.% of the LDPE, and at least 2 wt.% of the ethylene-based elastomer, based on the total weight of the polyethylene composition.

[0011] In a second aspect, a film is disclosed. The film can comprise the polyethylene composition according to the first aspect.

[0012] DETAILED DESCRIPTION

[0013] As used herein, the term “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), and the term copolymer or interpolymer. 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.

[0014] As used herein, the term “copolymer” means a polymer formed by the polymerization reaction of at least two structurally different monomers. The term “copolymer” is inclusive of terpolymers.

[0015] As used herein, the terms “polyethylene” or “ethylene-based polymer” shall mean a polymer comprising a majority amount (>50 mol %) of units which have been derived from ethylene monomer. This includes polyethylene homopolymers and copolymers (meaning units derived from two or more comonomers). The terms “ethylene-based polymer” and “polyethylene” may be used interchangeably. Generally, polyethylene may be produced in gas-phase, fluidized bed reactors, liquid phase slurry process reactors, or liquid phase solution process reactors, using a heterogeneous catalyst system, such as Ziegler-Natta catalyst, a homogeneous catalyst system, comprising Group 4 transition metals and ligand structures such as metallocene, non-metallocene metal-centered, heteroaryl, heterovalent aryloxyether, phosphinimine, and others. Combinations of heterogeneous and / or homogeneous catalysts also may be used in either single reactor or dual reactor configurations.

[0016] As used herein, the term “linear low density polyethylene” or “LLDPE”, includes resin made using the traditional Ziegler-Natta catalyst systems and chromium-based catalyst systems as well as single-site catalysts, including, but not limited to, substituted mono- or bis- cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, phosphinimine catalysts & polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy), and includes 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 5,272,236, U.S. Patent 5,278,272, U.S. Patent 5,582,923 and US Patent 5,733,155; the homogeneously branched linear ethylene polymer compositions such as those 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 US 3,914,342 or US 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. The LLDPE, as used herein, have a density in the range of 0.900 to 0.940 g / cc.

[0017] The term “low density polyethylene” or “LDPE” as used herein refers to as “high pressure ethylene polymer” or “highly branched polyethylene” and is defined to mean that the polymer is partly or entirely homo-polymerized or copolymerized in autoclave or tubular reactors at pressures above 14,500 psi (100 MPa) with the use of free-radical initiators, such as peroxides (see for example US 4,599,392, which is hereby incorporated by reference). The LDPE, as used herein, have a density in the range of 0.910 to 0.940 g / cm3. The LDPE can have a range of 0.916 to 0.929 g / cm3.

[0018] The terms “high density polyethylene” or “HDPE” refers to polyethylenes having densities greater than about 0.935 g / cm3and up to about 0.970 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chrome catalysts, or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, phosphinimine catalysts & polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy).

[0019] The term “composition,” as used herein, refers to a mixture of materials that comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition.

[0020] The term “recycled polyethylene composition,” as used herein, is a polyethylene that has been exposed to at least one heat history (e.g., via previous extrusion or conversion or melting into an article). Non-limiting examples of recycled polyethylene compositions include Post Consumer Recycled (“PCR”) compositions such as HDPE PCR polyethylene compositions sold under the KW Plastics and RENUVA™ trademarks as well as Reciclar Plastics (Argentina). The “high density recycled polyethylene composition” according to embodiments disclosed herein is a recycled polyethylene composition having a density greater than 0.940g / cc and a melt index (12) of less than 2.50 g / 10 min, according to ASTM D1238 (2.16 kg and 190°C). The term “ethylene / a-olefin copolymer” shall mean an ethylene-based polymer comprising at least one alpha-olefin comonomer that is polymerized with ethylene to make the copolymer. As such, an ethylene / a-olefin copolymer includes terpolymers, unless expressly excluded. Alpha-olefin comonomers include C3-C20 alpha-olefins, especially propene, isobutylene, 1 -butene, 1- hexene, 4-methyl-l -pentene, 1 -heptene, 1 -octene, 1 -nonene, and 1- decene, 1 -butene, 1 -hexene, 4-methyl-l -pentene and 1 -octene.

[0021] The term “ethylene-based elastomer” shall mean an ethylene / a-olefin copolymer that (i) comprise units derived from ethylene and units derived from at least one C3-C10 a-olefin comonomer, or at least one C4-C8 a-olefin comonomer, or at least one C6-C8 a-olefin comonomer; and (ii) has a density from 0.865 g / cm5, or 0.870 g / cm5, or 0.880 g / cm5, or 0.890 g / cm5to 0.900 g / cm5, or 0.902 g / cm5, or 0.904 g / cm5, or 0.909 g / cm5, or 0.910 g / cm5. This includes substantially linear, or linear, ethylene / a-olefin copolymers containing homogeneous short-chain branching distribution and ethylene / a-olefin multi-block copolymers. Nonlimiting examples of ethylene-based elastomers include commercially available plastomers or elastomers such as ENGAGE™ Polyolefin Elastomers, and INFUSE™ Olefin Block Copolymers (available from The Dow Chemical Company), EXACT™ elastomers (available from ExxonMobil Chemical), Tafmer (available from Mitsui), Nexlene™ (available from SK Chemicals Co.), and Lucene™ (available LG Chem Ltd.).

[0022] 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.

[0023] Disclosed herein are polyethylene compositions and a film including the polyethylene composition. The polyethylene composition comprises a high density recycled polyethylene composition having a density of at least 0.940 g / cc and a melt index (L) of less than 2.50 g / 10 min; a low density polyethylene (LDPE) having a density from 0.910 to 0.930 g / cc; and an ethylene-based elastomer having a density of less than 0.900 g / cc; and wherein the polyethylene composition comprises at least 30 wt.% of the high density recycled polyethylene composition, at least 5 wt.% of the LDPE, and at least 2 wt.% of the ethylene-based elastomer, based on the total weight of the polyethylene composition.

[0024] The high density recycled polyethylene composition (referred herein also as “HDR”) has a density of at least 0.940 g / cc and a melt index (I2) of less than 2.50 g / 10 min. In some embodiments, the HDR is a polyethylene recovered from post-consumer material as defined by ISO 14021 , polymers recovered from pre-consumer material as defined by ISO 14021 , or combinations thereof. In some embodiments, the HDR is a post-consumer recycled polyethylene or a post-industrial recycled polyethylene. The HDR can have a density of at least 0.940, at least 0.945, at least 0.950, at least 0.955 g / cc. The HDR can have a density of at most 0.970, 0.965, or 0.960 g / cc. The HDR can have a melt index (L) of less than 2.50 g / 10 min, less than 2.00 g / 10 min, less than 1.50 g / 10 min, less than 1.00 g / 10 min, less than 0.50 g / 10, or less than 0.30 g / 10 min. The HDR can have a melt index (I2) of at least 0.05, at least 0.10, or at least 0.20 g / 10 min. The polyethylene composition can comprise at least 35 wt.%, at least 40 wt.%, at least 45 wt.%, at least 50 wt.%, at least 55 wt.%, at least 60 wt.%, or at least 65 wt.%, of the HDR, based on the total weight of the composition. The polyethylene composition can comprise at most 85 wt.%, or at most 80 wt.%, or at most 75 wt.%, or at most 70 wt.%, of the HDR, based on the total weight of the composition.

[0025] The polyethylene composition comprises a low density polyethylene (LDPE) having a density from 0.910 to 0.930 g / cc. The LDPE can have a density of at least 0.910 g / cc or 0.915 g / cc. The LDPE can have a density of at most 0.930 g / cc or at most 0.925 g / cc. The LDPE can have a melt index (12) of less than 7.00 g / 10 min, or less than 6.00 g / 10 min, or less than 5.00 g / 10 min, or less than 4.00 g / 10 min, or less than 3.00 g / 10 min, or less than 2.00 g / 10 min, or less than 1.00 g / 10 min. The LDPE can have a melt index (12) of at least 0.05 g / 10 min, at least 0.10 g / 10 min, or at least 0.15 g / 10 min, or at least 0.20 g / 10 min. The composition can comprise at least 5 wt.% of the LDPE, at least 10 wt.%, at least 15 wt.%, at least 20 wt.%, at least 30 wt.%, at least 40 wt.% of the LDPE, based on the total weight of the polyethylene composition. The polyethylene composition can comprise at most 48 wt.% LDPE, at most 45 wt.%, at most 40 wt.%, at most 35 wt.%, at most 30 wt.%, or at most 25 wt.%, based on the total weight of the polyethylene composition.

[0026] The polyethylene composition comprises an ethylene-based elastomer having a density of less than 0.900 g / cc. The ethylene-based elastomer can have a density of less than 0.900 g / cc, less than 0.895 g / cc, less than 0.890 g / cc, less than 0.885 g / cc, less than 0.880 g / cc, or less than 0.875 g / cc. The ethylene-based elastomer can have a density of at least 0.850 g / cc, at least 0.855 g / cc, at least 0.860 g / cc, or at least 0.865 g / cc. The ethylene-based elastomer can have a melt index (12) of less than 1500 g / 10 min, or less than 1000 g / 10 min, less than 500 g / 10 min, less than 50 g / lOmin, less than 5.00 g / 10 min, or less than 2.00 g / 10 min. The ethylene-based elastomer can have a melt index (12) of at least 0.05 g / 10 min, at least 0.50 g / 10 min, or at least 0.75 g / 10 min. The polyethylene composition can comprise at least 2 wt.%, at least 5 wt.%, at least 10 wt.% of the ethylene-based elastomer, based on the total weight of the polyethylene composition. The polyethylene composition can comprise at most 20 wt.%, at most 18 wt.%, at most 15 wt.%, at most 12 wt.%, of the ethylene-based elastomer, based on the total weight of the polyethylene composition.

[0027] The polyethylene composition can have a molecular weight distribution (Mw / Mn) of less than 15.0, or less than 14.0, or less than 13.0, or less than 12.0, or less than 11.0. In some embodiments, the polyethylene composition has at least one of the following: a Mw of less than 190,000 g / mol; a Mn of greater than 13,000; and a Mz of less than 1,100,000. In some embodiments, the polyethylene composition has a unimodal molecular weight distribution. In some embodiments, the polyethylene composition has a bimodal molecular weight distribution. In some embodiments, the polyethylene composition has an enthalpy of melting (A Heat) of less than 195 J / g or less than 190 J / g, or less than 185 J / g. In some embodiments, the polyethylene composition has a first melting temperature (Tml), and the difference between an enthalpy of melting (A Heat) and the first melting temperature (Tml) is less than 61. In some embodiments, the polyethylene composition comprises from 55 to 75 wt.% of the high density recycled polyethylene composition, from 15 to 35 wt.% of the LDPE, and from 5 to 15 wt.% of the ethylenebased elastomer, based on the total weight of the polyethylene composition. The polyethylene composition can have a density from 0.930 g / cc to 0.950 g / cc, or from 0.935 g / cc to 0.945 g / cc.

[0028] The polyethylene composition is suitable for use in a film. A film comprising the polyethylene can be a blown film or a cast film. The film can be a multilayer film. In such embodiments, the multilayer film can comprise a first outer layer, a second outer layer, and one or more core layers, the one or more core layers positioned between the first outer layer and the second outer layer. The number of film layers is not particularly limited. For example, the film can have at least three layers, including a first outer layer, a first core layer, and a second outer layer. The position of the first core layer (e.g., when there are multiple core layers) is not particularly limited other than that it must be positioned between the first and second outer layers. In some embodiments, the multilayer film is a three layer film with a first outer layer, a second outer layer, and a first core layer. In one embodiment, the multilayer film comprises five layers, including a first outer layer, a first core layer, a second core layer, a third core layer, and a second outer layer (A / B / C / D / E, where A and E are outer layers). The film can have different thicknesses. In some embodiments, the film has a thickness 10 to 500 microns, or 20 to 350 microns, or 50 to 300 microns, or 180 to 260 microns.

[0029] A film can comprise at least 10 wt.% of the HDR, at least 15 wt.%, or at least 20 wt.%, based on the total weight of the film. A film can comprise at most 25 wt.%, at most 20 wt.%, or at most 15 wt.%, of the HDR based on the total weight of the film. The polyethylene composition can be part of the first core layer in multilayer film embodiments. For example, a film can comprise a first outer layer, a second outer layer, and a first core layer, wherein the first core layer comprises the polyethylene composition according to embodiments disclosed herein. In such embodiments, the first core layer can comprise at least 75 wt.% or at least 80 wt.% of the polyethylene composition and at least 3 wt.% or at least 10 wt.%, or at least 15 wt.% of a separate LDPE resin, based on the total weight of the first core layer. In such embodiments, the first outer layer and the second outer layer can each separately comprise a blend of LLDPE resin and LDPE resin, and the first core layer comprises the polyethylene composition and a separate LDPE resin.

[0030] Without being bound by theory, the polyethylene composition, when added to a film layer, the composition’s design of an ethylene-based elastomer, LDPE, and HDR can enhance composition compatibility and blend-ability without compromising performance with addition of the HDR. In particular, the composition and films comprising the composition can have low gel with good toughness and stiffness. For example, a film comprising the polyethylene composition can have at least one of the following properties: a gel level (G1200) of 15 to 22 defects count per 24.6 cm3; a tear strength in the CD of greater than 700 gf; a tear strength in the MD of greater than 160 gf; a puncture elongation at break greater than 70 mm; a puncture force max of greater than 64 N; an elongation at break in the CD greater than 800%; and an elongation at break in the MD greater than 650%.

[0031] In some film embodiments, a first outer layer and a second outer layer can each separately comprise a polyethylene. For example, in some embodiments, the first outer layer comprises at least one of a HOPE, LLDPE, or LDPE resin, and the second layer comprises at least one of a HDPE, LLDPE, or LDPE resin. The term “outer” confers that the layer is on a surface or skin of the film and is not a descriptor for whether a layer is on the outside or inside of an article covered by a film. In some embodiments, the film comprises at least 90 wt.%, at least 95 wt.%, at least 99 wt.%, of ethylene-based polymers (including the HDR). In some embodiments, the first outer layer comprises at least 30 wt.%, at least 40 wt.%, at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, of a LDPE, based on the total weight of the first outer layer. In some embodiments, the first outer layer comprises less than 90 wt.%, less than 80 wt.%, or less than 70 wt.%, of LDPE, based on the total weight of the first outer layer. Similarly, the second outer layer, in some embodiments, comprises at least 30 wt.%, at least 40 wt.%, at least 50 wt.%, at least 60 wt.%, at least 70 wt.%, at least 80 wt.%, at least 90 wt.% of a LDPE, based on the total weight of the second outer layer. In some embodiments, the second outer layer comprises less than 90 wt.%, less than 80 wt.%, or less than 70 wt.%, of a LDPE, based on the total weight of the second outer layer. In some embodiments, the first and / or second outer layer each consists essentially of low density polyethylene (LDPE).

[0032] In some embodiments, the first outer layer and second outer layer each comprise separately a LDPE. For examples, the first outer layer and / or the second outer layer can comprise at least 30 wt.%, at least 40 wt.%, at least 50 wt.%, of a LDPE, based on the total weight of the first outer layer and / or second outer layer. The first outer layer and / or second outer layer can comprise less than 90 wt.%, or less than 80 wt.%, of a LDPE, based on the total weight of the first outer layer and / or second outer layer.

[0033] A polyethylene film may generally be produced using techniques known to those of skill in the art based on the teachings herein. For example, the film may be produced by blown film coextrusion. The term “coextrusion” refers to the process of extruding two or more materials through a single die with two or more orifices arranged such that the extrudates merge together into a laminar structure, preferably before chilling or quenching. Coextrusion systems for making blown films employ at least two extruders feeding a common die assembly. The number of extruders is dependent upon the number of different materials comprising the coextruded film. For each different material, a different extruder can be used.

[0034] In some embodiments, the film or layers of the film may further comprise one or more additives. Additives are optionally included in the first inner layer, second inner layer, and / or core layers. Additives are well within the skill in the art. Such additives include, for instance, stabilizers including free radical inhibitors and ultraviolet wave (UV) stabilizers, neutralizes, nucleating agents, slip agents, antiblock agents, pigments, antistatic agents, clarifiers, waxes, resins, fillers such as silica and carbon black and other additives within the skill in the art used in combination or alone. Effective amounts are known in the art and depend on parameters of the polymers in the composition and conditions to which they are exposed. TEST METHODS

[0035] Density

[0036] Density is measured according to ASTM D792, Method B in reported in grams / cubic centimeter (g / cc or g / cm3).

[0037] Melt Index

[0038] Melt index (H), or 12, is measured in accordance with ASTM D1238, Conditions 190 °C / 2.16 kg, Procedure B; and the 12 value is reported in grams eluted per 10 minutes (g / 10 min).

[0039] MD and CD Elmendorf Tear Strength

[0040] ASTM D 1922-09 (average of 15 film samples in each direction; each sample “3 inx2.5 in” half-moon shape).

[0041] MD and CD Tensile Strength

[0042] ASTM D882-10 (average of five film samples in each direction; each sample “1 inx6 in”). 2% Secant Modulus-MD (machine direction) and CD (cross direction)

[0043] ASTM D882-10 (average of five film samples in each direction; each sample “1 inx6 in”).

[0044] Puncture Strength

[0045] Puncture is measured on an INSTRON. The specimen size is “6 inx6 in,” and four measurements are made to determine an average puncture value. The film is conditioned for 40 hours after film production, and at least 24 hours in an ASTM controlled laboratory (23° C. and 50% relative humidity. A “100 lb” load cell is used with a round specimen holder of 4 inch diameter. The puncture probe is a “J / 2 inch diameter” polished stainless steel ball (on a 2.5" rod) with a “7.5 inch maximum travel length.”

[0046] Defect Count

[0047] The Defect Count is a measure of defects that are detected in an extruded film using optical imaging technology according the practices and guidance in ASTM D7310-20 “Standard Practice for Defect Detection and Rating of Plastic Film Using Optical Sensors.” The Defect Count is reported as the number of optical defects per 24.6 cm3with an effective circular diameter within defined series of ranges: 200-400pm, 400- 800pm, 800- 1600pm, 1600pm and above. It is measured by an Optical Control Systems Film Surface Analyzer FSA100 (OCS FSA100) optical imaging system. The OCS FSA100 optical imaging system consists of a lighting unit, a CCD line scan camera, and a computer with image / data analysis software version 5.0.4.6. The OCS FSA100 optical imaging system detects defects as they obscure the transmission of halogen-based source light. Average greyscale was set to 170 with a threshold sensitivity setting of 35%. Additionally, the gain of the CCD system may be adjusted to compensate for film haziness. The imaging system creates a composite area of each defect by adding the defective pixels from each subsequent line scan. The system then reports the number of defects which were in user defined size ranges, based on the diameter of circles having equivalent areas. Film fabrication is accomplished by an OCS MEI 9 cast film extrusion system equipped with a fixed lip coat hanger die. Die gap is 500 jim by 15 cm. It is a single screw extruder equipped with a 19 mm screw provided by OCS. The screw design is a 3: 1 L / D compression ratio with a pineapple mixing tip. Total extrusion system mass output is 10 ± 5 kg / hour. Film thickness was 38 pm, which was achieved via adjustment of the chill roll. A nitrogen purge was used at the feed throat of the extruder. Temperature profiles ranged from 135 °C - 190 °C to achieve a target extrusion pressure of 220-240 Bar.

[0048] EXAMPLES

[0049] The below polymers in Table 1 are used in the examples. All of the polyethylene resins are commercially available from The Dow Chemical Company with exception of the HDPE PCR. The HDPE PCR is commercially available from Reciclar SA (Argentina).

[0050] Table 1: Raw Materials

[0051] Resins

[0052] Polyethylene compositions having the formula and density shown in Table 2 are made. The compositions listed are produced by dry blending the required proportions of the PCR HDPE resin and other polyethylene resins into the hopper from the single screw recycling line Wortex Challenge II, where they are conveyed, melted, and mixed. The mixer is equipped with devolatilization section to remove any volatiles. The mixed polymer melt is submitted to a screen changer equipped with screen packs having a combination of screens with the finest screen being 100 mesh to remove undesired contaminants. The filtered polymer melt is then flowed through the die holes and is pelletized using either an underwater pelletizer or a strand pelletizer. The cut pellets were then dewatered and dried and collected.

[0053] Table 2: Composition Formulations (wt.%)

[0054] The formulations are tested on DSC and GPC.

[0055] Table 3: DSC Data

[0056] Table 4: GPC Data

[0057] Films containing comparative resins, or the polyethylene compositions are produced using a 5-layer blown film extrusion in a configuration to obtain a 3-layer film composition (A / B / A) having a target thickness of 50 pm with a total output of 10 kg / h. The target temperature profile during extrusion is 190, 220, 235°C. The comparative or control film without the inventive polyethylene composition is shown below and designated as “CFO.” Tables 6 lists the core layer, “B” of the other comparative films and inventive films, where the “A” outer layers are the same as in CFO.

[0058] Table 5: CFO AND “A” and “C” - Standard Outer Layers Table 6: Core Layer Film Formulations

[0059] Film defect count is measured on the comparative and inventive films.

[0060] Table 7 - Film Defects

[0061] Film mechanical properties are measured. Table 8 reports the results.

[0062] Table 8 - Films

[0063] From film defects, it can be seen that inventive examples can show a reduction in terms of GI200 and large gels 1600, 800 and 200 m in contrast to many of comparative examples even when high density recycled polyethylene compositions are present. Regarding mechanical properties, it can be seen that inventive formulations provide better toughness, i.e. tear, puncture and elongation resistance while maintaining acceptable stiffness when compared to its comparative counterpart. This is certainly unexpected as the presence of low density PE materials is expected to significantly decrease overall formulation toughness / stiffness balance.

Claims

CLAIMSWe claim:

1. A polyethylene composition comprising:(a) a high density recycled polyethylene composition having a density greater than 0.940g / cc and a melt index (12) of less than 2.50 g / 10 min, according to ASTM D1238 (2.16 kg and 190°C);(b) a low density polyethylene (LDPE) having a density from 0.910 to 0.930 g / cc; and(c) an ethylene-based elastomer having a density of less than 0.900 g / cc; and wherein the polyethylene composition comprises at least 30 wt.% of the high density recycled polyethylene composition, at least 5 wt.% of the LDPE, and at least 2 wt.% of the ethylene-based elastomer, based on the total weight of the polyethylene composition.

2. The polyethylene composition of claim 1, wherein the polyethylene composition has an enthalpy of melting (A Heat) of less than 195 J / g.

3. The polyethylene composition of any one of the preceding claims, wherein the polyethylene composition has a first melting temperature (Tml), and the difference between an enthalpy of melting (A Heat) and the first melting temperature (Tml) is less than 61.

4. The polyethylene composition of any one of the preceding claims, wherein the ethylenebased elastomer has a melt index (L) of less than 500 g / 10 min.

5. The polyethylene composition of any one of the preceding claims, wherein the LDPE has a melt index (I2) of less than 7.00 g / 10 min.

6. The polyethylene composition of any one of the preceding claims, wherein the polyethylene composition has a molecular weight distribution (Mw / Mn) of less than 15.0.

7. The polyethylene composition of any one of the preceding claims, wherein the polyethylene composition comprises from 55 to 75 wt.% of the high density recycled polyethylene composition, from 15 to 35 wt.% of the LDPE, and from 5 to 15 wt.% of the ethylene-based elastomer, based on the total weight of the polyethylene composition.

8. The polyethylene composition of any one of the preceding claims, wherein the polyethylene composition has at least one of the following: a Mw of less than 190,000 g / mol; a Mn of greater than 13,000; and a Mz of less than 1,100,000.

9. The polyethylene composition of any one of the preceding claims, wherein the polyethylene composition has a unimodal molecular weight distribution.

10. A film comprising the polyethylene composition of any one of claims 1 to 9.

11. The film of claim 10, wherein the film is a blown film.

12. The film of claims 10 or 11, wherein the film comprises a first outer layer, a second outer layer, and a first core layer, wherein the first core layer comprises the polyethylene composition of claims 1 to 9.

13. The film of any one of claims 10 to 12, wherein the film comprises at least 10 wt.% of the high density recycled polyethylene composition.

14. The film of any one of claims 10-13, wherein the first core layer comprises at least 75 wt.% of the polyethylene composition and at least 3 wt.% of a LDPE resin, based on the total weight of the core layer.

15. The film of any one of claims 12-14, wherein the first outer layer and the second outer layer each separately comprise a blend of LLDPE resin and LDPE resin, and the first core layer comprises the polyethylene composition and a separate LDPE resin.

16. The film of any one of claims 11-15, wherein the film has at least one of the following properties: a gel level (G1200) of 15 to 22 defects count per 24.6 cm3; a tear strength in the CD of greater than 700 gf; a tear strength in the MD of greater than 160 gf; a puncture elongation at break greater than 70 mm; a puncture force max of greater than 64 N; an elongation at break in the CD greater than 800%; and an elongation at break in the MD greater than 650%.

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