Polyethylene recovery blend product

Abstract

A composition is provided that includes a blend of a first HDPE component having a relatively higher density and a lower molecular weight and a second HDPE component having a relatively lower density and a higher molecular weight. The blends exhibit improved ESCR performance at a given density relative to existing HDPE products.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 395,255, filed on August 4, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to blends of high density polyethylene recyclate and virgin high density polyethylene. Background Art

[0004] Polyolefins, in particular polyethylene, are increasingly consumed in many applications, including packaging of food and other goods, electronics, automotive components and various manufactured goods. Currently, a large amount of waste plastic materials comes from the differentiated recycling of urban plastic waste, which mainly consists of flexible packaging (cast film, blown film and BOPP film), rigid packaging, blow-molded bottles and injection-molded containers. Generally, polyethylene fractions, in particular high-density polyethylene (HDPE) recyclates, can be recovered through a separation step from other polymers such as polyvinyl chloride (PVC), polyethylene terephthalate (PET) or polystyrene (PS).

[0005] Applications for HDPE resins typically include, but are not limited to, small blow molding, caps and closures, tanks, high molecular weight films, injection molding, tubing, industrial bulk containers, etc. Direct reuse of such HDPE recyclates is often limited due to reduced crack resistance, melt strength, and / or impact strength relative to virgin HDPE of similar density and high load melt index. Through thermal and / or catalytic degradation of polymer recyclates, the monomer building blocks of the polymer can be recovered and used as feedstock to produce new polymers with desired properties. However, this requires additional processing steps that consume significant amounts of energy and, in some cases, produce undesirable byproducts that also require additional processing steps for proper disposal.

[0006] It would be desirable to be able to more directly return HDPE recyclate to commercial circulation while minimizing the additional processing steps required to do so. It would be desirable to provide methods for producing HDPE compositions comprising recycled HDPE, such HDPE compositions having a set of useful properties that are equal to or better than similar virgin HDPE compositions. Ideally, such methods would be highly flexible and could utilize commonly used equipment and familiar techniques to produce a wide variety of products. Summary of the invention

[0007] In general, the present disclosure relates to a composition comprising a blend of a first HDPE component and a second HDPE component. The first HDPE component has a relatively lower molecular weight and a higher density than the second HDPE component. In some embodiments, the blend has an environmental stress cracking resistance (ESCR) that is higher than that of virgin HDPE of similar density.

[0008] In some embodiments, the first HDPE component is present in an amount in the blend in a range of 40 wt.% to 95 wt.%, and the second HDPE component is present in an amount in the blend in a range of 5 wt.% to 60 wt.%, wherein the weight percentages are based on the total weight of the first HDPE component and the second HDPE component.

[0009] In some embodiments, the density of the first HDPE component is between 0.955 g / cm 3 Up to 0.965g / cm 3 The melt index (I5) is in the range of 1.50 g / 10 min to 3.50 g / 10 min, and the environmental stress crack resistance ("ESCR") F50 in 10% Igepal is in the range of 10 hours to less than 20 hours.

[0010] In some embodiments, the density of the second HDPE component is between 0.947 g / cm 3 Up to 0.954g / cm 3 The melt index (I5) is in the range of 0.10 g / 10 min to 1.50 g / 10 min, and the environmental stress crack resistance ("ESCR") F50 in 10% Igepal is greater than or equal to 1,000 hours.

[0011] In some embodiments, the density of the blend is between 0.951 g / cm 3 Up to 0.962g / cm 3 in the range of 0.5 to 1.0 hours, the melt index (I5) in the range of 0.60 g / 10 min to 2.50 g / 10 min, and the environmental stress crack resistance ("ESCR") F50 in 100% Igepal in the range of 24 hours to 1,000 hours and / or the environmental stress crack resistance ("ESCR") F50 in 10% Igepal in the range of 24 hours to 84 hours.

[0012] In some embodiments, the composition is prepared by melt mixing the first and second HDPE components, and optionally the primary and / or secondary antioxidants, to form a pelletized product.

[0013] The above content has been quite extensively summarized the features and technical advantages of the present invention so that the following detailed description of the present invention can be better understood. Other features and advantages of the present invention will be described below, which constitute the subject matter of the claims of the present invention. It should be understood by those skilled in the art that the disclosed concepts and specific embodiments can be easily used as the basis for modifying or designing other membrane structures and / or processes for achieving the same purpose of the present invention. It should also be recognized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the present invention as set forth in the appended claims. The novel features of its structure and manufacturing method and further objects and advantages that are considered to be features of the present invention will be better understood from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The claimed subject matter may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:

[0015] Figure 1 An overlay graph showing the ESCR performance of HDPE blends according to embodiments of the present invention compared to other similar HDPE blends;

[0016] Figure 2 showing the ESCR performance of the blends disclosed herein using a pristine first HDPE component compared to other HDPEs; and

[0017] Figure 3 showing the ESCR performance of the blends disclosed herein using a recycled first HDPE component compared to other HDPEs; and

[0018] Figure 4 The diameter expansion performance of HDPE blends according to embodiments of the present invention are shown compared to a benchmark diameter expansion range.

[0019] Although the disclosed methods and compositions are susceptible to various modifications and alternative forms, the accompanying drawings illustrate specific embodiments described in detail herein by way of example. However, it should be understood that the description of specific embodiments herein is not intended to limit the invention to the particular forms disclosed, but rather, the invention is intended to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. DETAILED DESCRIPTION

[0020] Illustrative embodiments of the claimed subject matter will now be disclosed. For the sake of clarity, some features of some actual implementations may not be described in this specification. It will be appreciated that in the process of developing any such actual implementation, many implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system and business-related constraints, which may vary from one implementation to another. Moreover, it will be appreciated that such development work, even if complex and time-consuming, is a routine undertaking for a person of ordinary skill in the art having the benefit of this disclosure.

[0021] The words and phrases used herein should be understood and interpreted as having a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. A special definition of a term or phrase, i.e., a special definition of a term or phrase that is different from the ordinary and customary meaning as understood by those skilled in the art, is a definition that is different from the ordinary and customary meaning as understood by those skilled in the art. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning that is different from the broadest meaning as understood by those skilled in the art, such a special or clear definition will be clearly set forth in the specification in a definitional manner that provides a special or clear definition of the term or phrase. It must also be noted that, as used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural references unless otherwise indicated.

[0022] For example, the following discussion contains a non-exhaustive list of definitions of several specific terms used in this disclosure (other terms may be defined or clarified in the manner defined elsewhere herein). These definitions are intended to clarify the meaning of the terms used herein. It is believed that the terms are used in a manner consistent with their ordinary meanings, but for clarity, the definitions are specified here.

[0023] definition

[0024] As used herein, "antioxidant" refers to a compound that inhibits oxidation, chemical reactions and chain reactions that can produce free radicals. Antioxidants are classified according to their reaction mechanism and include: (1) primary antioxidants, and (2) secondary antioxidants.

[0025] As used herein, "compounding conditions" refers to the temperature, pressure, and shear conditions effected in an extruder to provide intimate mixing of two or more polymers and optionally additives to produce a substantially homogeneous polymer product.

[0026] As used herein, "HDPE recycle" refers to a portion of polyolefin recycle having a density of 0.940 g / cm 3 Up to 0.970g / cm 3 within the range.

[0027] As used herein, "HDPE" means ethylene homopolymers and ethylene copolymers produced in gas phase and / or slurry phase polymerization, the ethylene homopolymers and ethylene copolymers having a density of 0.940 g / cm 3 Up to 0.970g / cm 3 within the range.

[0028] As used herein, "polyolefin recyclate" means post-consumer recycled ("PCR") polyolefins and / or post-industrial recycled ("PIR") polyolefins. Polyolefin recyclate is derived from end products that have completed their life cycle as consumer products and would otherwise be disposed of as waste (e.g., polyethylene water bottles), or from plastic waste generated by waste from industrial processes. Post-consumer polyolefins include polyolefins that have been collected in commercial recycling programs and residential recycling programs, including flexible packaging (cast film, blown film, and BOPP film), rigid packaging, blow molded bottles, and injection molded containers. Typically, two major polyolefin fractions, polyethylene recyclate (including HDPE, MDPE, LDPE, and LLDPE) and polypropylene recyclate (including homopolymers, random copolymers, and heterophasic copolymers), are obtained by a step of separation from other polymers such as nylon, polyamide, PVC, PET, or PS. Polyethylene recyclate can be further separated to recover a portion having polyolefins as a major component. In addition to contamination from different polymers, polyolefin recyclates often contain other impurities such as PMMA, PC, wood, paper, textiles, cellulose, food, and other organic wastes, many of which cause the polyolefin recyclate to have an unpleasant odor before and after typical processing.

[0029] As used herein, "primary antioxidant" refers to a compound that essentially acts as a free radical terminator or scavenger. Primary antioxidants react rapidly with peroxides and alkoxy groups. Most primary antioxidants used for polymers are sterically hindered phenols.

[0030] As used herein, "processability" refers to the degree to which a polymer composition can be formed into blown films of commercial quality or into molded articles of commercial quality by injection or compression molding at a commercially acceptable rate using equipment and conditions.

[0031] As used herein, "secondary antioxidant" refers to a preventive antioxidant that acts to delay chain initiation. Secondary antioxidants react with hydroperoxides to form non-radical products and are therefore often referred to as hydroperoxide decomposers.

[0032] "Virgin HDPE" as used herein is pre-consumer HDPE. Pre-consumer HDPE is a product obtained directly or indirectly from a petrochemical feedstock fed to a polymerization unit. Pre-consumer polyolefins may be subjected to post-polymerization treatments, including but not limited to extrusion, pelletizing, peroxidation, visbreaking, and / or other treatments before reaching the end consumer. In some embodiments, the virgin polyolefin has a single thermal history. In some embodiments, the virgin polyolefin has multiple thermal histories. In some embodiments, the virgin polyolefin does not include additives. In some embodiments, the virgin polyolefin includes additives.

[0033] HDPE blend composition

[0034] Disclosed herein are compositions comprising a blend of a first HDPE blending component and a second HDPE blending component, wherein the first HDPE component has a relatively higher density and a lower molecular weight than the second HDPE component.

[0035] In some embodiments, the content of the first HDPE component in the blend is in the range of 40 wt.% to 95 wt.%, 50 wt.% to 90 wt.%, 60 wt.% to 85 wt.%, or 70 wt.% to 80 wt.%. Accordingly, the content of the second HDPE component in the blend is in the range of 5 wt.% to 60 wt.%, 10 wt.% to 50 wt.%, 15 wt.% to 40 wt.%, or 20 wt.% to 30 wt.%. All weight percentages are based on the total weight of the first HDPE component and the second HDPE component.

[0036] In some embodiments, the blend composition has one or more of the following:

[0037] a) Density is 0.951 g / cm 3 Up to 0.962g / cm 3 or 0.956 g / cm 3 Up to 0.960g / cm 3 within the scope of

[0038] b) a melt index (I5) in the range of 0.60 g / 10 min to 2.50 g / 10 min or 0.80 g / 10 min to 1.80 g / 10 min; and

[0039] c) an environmental stress crack resistance ("ESCR") F50 in 100% Igepal in the range of 24 hours to 1,000 hours and / or an environmental stress crack resistance ("ESCR") F50 in 10% Igepal in the range of 24 hours to 84 hours.

[0040] In some embodiments, the blend composition has one or more of the following:

[0041] a) Number average molecular weight (M n ) is in the range of 10,000 g / mol to 20,000 g / mol;

[0042] b) Weight average molecular weight (M w ) is in the range of 130,000 g / mol to 230,000 g / mol or 156,000 g / mol to 194,000 g / mol;

[0043] c) a molecular weight distribution (MWD) in the range of 8 to 20 or 10 to 15;

[0044] d) a high load melt index (HLMI) in the range of 15 g / 10 min to 45 g / 10 / min or 20 g / 10 min to 40 g / 10 / min; and

[0045] e) 2% flexural modulus is in the range of 165,000 psi (1,138 MPa) to 215,000 psi (1,482 MPa) or 175,000 psi (1,207 MPa) to 205,000 psi (1,413 MPa).

[0046] In some embodiments, the blend composition has one or more of the following:

[0047] a) a population polydispersity ratio (PDR) in the range of 15 to 60 or;

[0048] b) Zero shear viscosity (η0) is 1.0x10 6 Up to 3.0x10 7 within the scope of

[0049] c) a bulk intrinsic viscosity ([η]) in the range of 1.5 to 2.5; and

[0050] d) The long chain branching index (LCBI) is in the range of 0.3 to 1.3.

[0051] In some embodiments, the first HDPE component and the second HDPE component are melt blended at a temperature in the range of 150°C to 250°C to form the composition.

[0052] In some embodiments, the blend further comprises a primary antioxidant, a secondary antioxidant, or a combination thereof. In other embodiments, the primary antioxidant is present in the blend at a level less than or equal to 1500 ppm, and the secondary antioxidant is present in the blend at a level less than or equal to 1500 ppm, wherein the ppm value is based on the total weight of the first HDPE component and the second HDPE component.

[0053] Figure 1 The overall trend for the FHC / SHC blends disclosed herein is shown, which exhibit improved ESCR compared to HDPE recycled blends with typical unimodal Cr-HDPE (produced using chromium catalysts) or typical multimodal HDPE.

[0054] - The first HDPE blend composition

[0055] The density of the first HDPE component is between 0.955 g / cm3 and 0.966 g / cm 3 In the range of 1.50 g / 10 min to 3.50 g / 10 min, the melt index (I5) is / 1 0 min, and ESCR F50 is less than 24 hours at 100% Igepal.

[0056] In some embodiments, the first HDPE component has one or more of the following:

[0057] a) Number average molecular weight (M n ) is in the range of 8,000 g / mol to 20,000 g / mol or 12,000 g / mol to 16,000 g / mol;

[0058] b) Weight average molecular weight (M w ) is in the range of 100,000 g / mol to 170,000 g / mol or 115,000 g / mol to 145,000 g / mol;

[0059] c) a molecular weight distribution (MWD) in the range of 5 to 14 or 6 to 9;

[0060] d) a high load melt index (HLMI) in the range of 35 g / 10 min to 70 g / 10 / min or 40 g / 10 min to 65 g / 10 / min; and

[0061] e) Average molecular weight (M) z ) is in the range of 500,000 g / mol to 2,000,000 g / mol;

[0062] f)z+1 average molecular weight (M z+1) in the range of 1,000,000 g / mol to 3,500,000 g / mol; and

[0063] g) 2% flexural modulus is in the range of 170,000 psi (1,172 MPa) to 230,000 psi (1,586 MPa) or 180,000 psi (1,241 MPa) to 210,000 psi (1,778 MPa).

[0064] In some embodiments, the first HDPE component has one or more of the following: a zero shear viscosity (η0) of 1.1 x 10 7 Up to 1.6x10 7 in the range of , the bulk intrinsic viscosity ([η]) in the range of 1.40 to 1.75, the viscosity ratio in the range of 0.800 to 1.100 and the long chain branching index (LCBI) in the range of 0.6 to 2.0.

[0065] In some embodiments, the first HDPE component comprises one or more HDPE homopolymers, one or more HDPE copolymers, or combinations thereof.

[0066] In some embodiments, the first HDPE component comprises one or more HDPE recyclates, one or more virgin HDPEs, or a combination thereof.

[0067] In some embodiments, the first HDPE component comprises one or more HDPE homopolymer recyclates, one or more HDPE copolymer recyclates, or a combination thereof.

[0068] - Second HDPE blend composition

[0069] The density of the second HDPE component is 0.947 g / cm 3 Up to 0.954g / cm 3 The melt index (I5) is in the range of 0.10 g / 10 min to 1.50 g / 10 min, and the ESCR F50 in 100% Igepal is greater than or equal to 1,000 hours.

[0070] In some embodiments, the second HDPE component has one or more of the following: a density at least 0.003 g / cm2 less than the density of the first HDPE component. 3 , I5 is at least 0.02 g / 10 min lower than the I5 of the first HDPE component; and ESCR F50 in 100% Igepal is at least 100 hours longer than the ESCR of the first HDPE component.

[0071] In some embodiments, the second HDPE component has one or more of the following:

[0072] a) Number average molecular weight (M n ) is in the range of 9,000 g / mol to 25,000 g / mol or 12,000 g / mol to 22,000 g / mol;

[0073] b) Weight average molecular weight (M w ) is in the range of 150,000 g / mol to 350,000 g / mol or 200,000 g / mol to 300,000 g / mol;

[0074] c) a molecular weight distribution (MWD) in the range of 5 to 40 or 7 to 30;

[0075] d) a high load melt index (HLMI) in the range of 5 g / 10 min to 40 g / 10 / min or 7 g / 10 min to 30 g / 10 / min;

[0076] Average molecular weight (M z ) is in the range of 500,000 g / mol to 2,000,000 g / mol;

[0077] f)z+1 average molecular weight (M z +1) in the range of 1,000,000 g / mol to 3,500,000 g / mol; and g) 2% flexural modulus in the range of 120,000 psi (827 MPa) to 170,000 psi (1,172 MPa) or 136,000 psi (938 MPa) to 146,000 psi (1,007 MPa).

[0078] In some embodiments, the second HDPE component has one or more of the following: a zero shear viscosity (η0) of 1.0 x 10 5 Up to 1.0x10 8 in the range of , the bulk intrinsic viscosity ([η]) in the range of 1.80 to 3.00, the viscosity ratio in the range of 0.800 to 1.100 and the long chain branching index (LCBI) in the range of 0.1 to 2.0.

[0079] In some embodiments, the second HDPE component comprises one or more HDPE homopolymers, one or more HDPE copolymers, or combinations thereof.

[0080] -High-density polyethylene

[0081] In some embodiments, the HDPE described herein comprises units derived from ethylene and units derived from one or more C3-C 12 Homopolymers and / or copolymers of α-olefin units. 12 Alpha-olefins include, but are not limited to, substituted or unsubstituted C3 to C 12 α-olefins such as propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecane and isomers thereof. When present, the comonomer may be present in an amount up to 20 wt.%, 15 wt.%, 10 wt.% or 5 wt.%.

[0082] Such ethylene homopolymers and / or copolymers can be produced in suspension, solution, slurry or gas phase processes using known equipment and reaction conditions. In some embodiments, the polymerization temperature is in the range of about 0°C to about 300°C at a pressure of about 1 psig (6.9 kPag) to 1,000 psig (6.9 MPag).

[0083] Slurry or solution polymerization systems can utilize negative pressure (less than 1 atm or ~14.7 psig, or 1 to less than 14.7 psig), atmospheric pressure (about 1 atm or ~14.7 psig), or superatmospheric pressure (greater than 1 atm or ~14.7 psig, or greater than 1 to about 1,000 psig) and temperatures in the range of about 40°C to about 300°C. Exemplary liquid phase polymerization systems are described in U.S. Pat. No. 3,324,095, the disclosure of which is incorporated herein by reference in its entirety. Liquid phase polymerization systems typically include a reactor to which olefin monomers and a catalyst composition are added, and which contains a liquid reaction medium for dissolving or suspending the polyolefin. The liquid reaction medium may be composed of bulk liquid monomers or an inert liquid hydrocarbon that is non-reactive under the polymerization conditions employed. Although such an inert liquid hydrocarbon need not be used as a solvent for the catalyst composition or the polymer obtained by the process, it is typically used as a solvent for the monomers employed in the polymerization. Inert liquid hydrocarbons suitable for this purpose are isopentane, hexane, cyclohexane, heptane, benzene, toluene, etc. The reactive contact between the olefin monomer and the catalyst composition should be maintained by constant stirring or agitation. The reaction medium containing the olefin polymer product and unreacted olefin monomer is continuously discharged from the reactor. The olefin polymer product is separated, and unreacted olefin monomer and liquid reaction medium are recycled in the reactor.

[0084] Gas phase polymerization systems can utilize pressures in the range of 1 psig (6.9 kPag) to 1,000 psig (6.9 MPag), 50 psig (344 kPag) to 400 psig (2.8 MPag), or 100 psig (689 kPag) to 300 psig (2.1 MPag) and temperatures in the range of 30°C to 130°C or 65°C to 110°C. The gas phase polymerization system can be a stirred or fluidized bed system. In some embodiments, a gas phase fluidized bed process is performed by continuously passing a stream containing one or more olefin monomers through a fluidized bed reactor under reaction conditions and in the presence of a catalyst composition at a rate sufficient to maintain a bed of solid particles in suspension conditions. The stream containing unreacted monomers is continuously discharged from the reactor, compressed, cooled, optionally partially or completely condensed, and recycled to the reactor. The product is discharged from the reactor and make-up monomer is added to the recycle stream. Any gas inert to the catalyst composition and reactants may also be present in the gas stream as required for temperature control of the polymerization system.

[0085] In some embodiments, a catalyst based on a VIB Group metal is used. In some embodiments, the catalyst is a chromium-based catalyst. Such HDPE homopolymers and / or copolymers have some long chain branching and a density of 0.940 g / cm3 To 0.970g / cm3 within the range.

[0086] In some embodiments, Ziegler-Natta (ZN) catalysts are used. Such catalysts are based on Group IVB transition metal compounds and organoaluminum compounds (cocatalysts). Such transition metals include, but are not limited to, Ti, Zr, and Hf. Non-limiting examples of ZN catalyst systems include TiCl4+Et3Al and TiCl3+AlEt2Cl. Such HDPE homopolymers and / or copolymers have some long chain branching and a density of 0.940 g / cm 3 Up to 0.970g / cm 3 within the range.

[0087] In some embodiments, the HDPE described herein is prepared according to the methods and conditions in U.S. Pat. No. 9,249,286 and U.S. Pat. No. 10,501,613, the disclosures of which are incorporated herein by reference in their entirety. In some embodiments, the HDPE described herein is prepared according to the methods and conditions in PCT published patents Nos. WO20140134193, WO20160206959, WO20160206958, WO20160206957, and WO20190121234, the disclosures of which are incorporated herein by reference in their entirety. In another embodiment, the HDPE described herein is prepared according to the methods and conditions in “Introduction to Industrial Polyethylene” by Dennis B. Malpass (2010), the disclosures of which are incorporated herein by reference in their entirety. For example, a HDPE having the ESCR, zero shear viscosity, bulk intrinsic viscosity and / or LCBI properties described herein can be prepared using a chromium catalyst under system conditions such as operating pressure of about 590-620 PSI, operating temperature of about 205-230F, and residence time of about 0.7-0.9 hours.

[0088] - Compounding Extruder

[0089] In some embodiments, the first HDPE component and the second HDPE component are fed into an extruder or mixer, where the blend is placed under compounding conditions. Compounding conditions are implemented in an extruder or mixer and are tailored for a mixture of a specific polyolefin and optionally additives such as, but not limited to, one or more primary antioxidants, one or more secondary antioxidants, and / or peroxides. The temperature, pressure, and shear conditions implemented in the second extruder or mixer are sufficient to thoroughly mix the first HDPE component and the second HDPE component and optionally additives to produce a substantially uniform polymer blend of the first HDPE component and the second HDPE component. In some embodiments, compounding conditions include a temperature in the compounding zone of less than or equal to 300°C, less than or equal to 250°C, or less than or equal to 200°C. In some embodiments, the temperature in the compounding zone may be in the range of 130°C to 280°C, 140°C to 265°C, or 150°C to 250°C.

[0090] -Antioxidants

[0091] In some embodiments, primary antioxidants and / or secondary antioxidants are added to stabilize the reaction upon any exposure to oxygen during the compounding process.

[0092] Primary antioxidants react rapidly with peroxyl radicals and alkoxyl radicals. Examples of primary antioxidants (sometimes referred to as "long-term antioxidants") include phenolic antioxidants and hindered amine antioxidants, such as those disclosed in U.S. Pat. No. 6,392,056, the disclosure of which is incorporated herein in its entirety. Suitable primary antioxidants include, but are not limited to, Irganox available from BASF TM Antioxidants, such as Irganox TM 1010, Irganox TM 1076. Irganox TM 1098, Irganox TM 1330, Irganox TM 1425WL, Irganox TM 3114、Irganox TM 245 and Irganox TM 1135. Examples of suitable antioxidants, including phenolic antioxidants and hindered amine antioxidants, are described in U.S. Pat. No. 7,285,617, the disclosure of which is incorporated herein in its entirety.

[0093] Non-limiting examples of primary antioxidants include 2,6-di-tert-butyl-4-methylphenol, pentaerythritol-tetrakis(3-(3',5'-di-tert-butyl-4-hydroxyphenyl)-propionate, octadecyl 3-(3',5'-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tri-(3,5-di-tert-butyl-4-hydroxyphenyl)benzene, 1,3,5-tris(3',5'-di-tert-butyl-4-hydroxyphenyl)propionate, butyl-4'-hydroxybenzyl)-isocyanurate, bis-(3,3-bis-(4-'-hydroxy-3'-tert-butylphenyl) butyric acid)-ethylene glycol ester, N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy)-hydrocinnamic acid, 2,5,7,8-tetramethyl-2(4',8',12'-trimethyltridecyl)chroman-6-ol, 2,2'-ethylenebis(4,6-di-tert-butyl) phenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,-6-(1H,3H,5H)-trione, 3,9-bis(1,1-dimethyl-2-(β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy)ethyl)-2,4,8 ,10-tetraoxaspiro(5,5)undecane, 1,6-hexanediyl-bis(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenylpropionate), 2,6-di-tert-butyl-4-nonylphenol, 4,4'-butylenebis(6-tert-butyl-3-methylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol) and triethylene glycol ether-bis(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate.

[0094] Secondary antioxidants, sometimes called "short-term antioxidants", can be added to the mixer / extruder at any convenient point. Secondary antioxidants are commercially available, for example, as Irgafos from BASF. TM Antioxidants, such as Irgafos TM 168. Irgafos TM 126. Irganox TM PS 800 and Irganox TM PS 802.

[0095] Examples of secondary antioxidants include, for example, aliphatic mercaptans, phosphites, and phosphites (III). Specific examples of secondary antioxidants include distearyl pentaerythritol diphosphite, isodecyl diphenyl phosphite, diisodecyl phenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, dilauryl-β,β-thiodipropionate, β-naphthyl disulfide, thiol-β-naphthol, 2-mercaptobenzothiazole, benzothiazolyl disulfide, phenothiazine, tris (p-nonylphenyl) phosphite, and zinc dimethyldithiocarbamate.

[0096] -peroxide

[0097] In some embodiments, peroxide modified resins may be used in the blend. Peroxide treatment conditions are implemented in an extruder. In some embodiments, peroxide treatment conditions refer to subjecting the mixture of HDPE and peroxide to pressure, temperature, and shear conditions sufficient to react the peroxide with the HDPE, resulting in polymer chain scission and / or attachment of some polymer chains along the backbone of other polymer chains, thereby producing long chain branching.

[0098] In some embodiments, the amount of the peroxide free radical initiator added to the polyethylene composition is in the range of 0.1 to 100 ppm (by weight) relative to the polyethylene composition, or in the range of 0.5 to 100 ppm (by weight). In some embodiments, the amount of the peroxide free radical initiator added to the polyethylene composition is determined by rheology or by film testing. In some embodiments, the amount of the peroxide free radical initiator added to the polyethylene composition is determined by the expected change in rheological polydispersity ER. In some embodiments, the amount of the free radical initiator added to the polyethylene composition is determined by bubble stability testing.

[0099] In some embodiments, the first HDPE component, the second HDPE component, and / or the composition are treated with a peroxide in an extruder under conditions including temperature, pressure, and shear sufficient to increase long chain branching, thereby improving the processability of the first polyethylene component, the second polyethylene component, and / or the composition, as appropriate. The blended composition may also be treated with a peroxide during blending of the first HDPE component and the second HDPE component in an extruder or mixer under compounding conditions. Improving the processability of the first HDPE component and / or the second HDPE component prior to blending will improve the processability of the composition after the components are blended.

[0100] In some embodiments, the first HDPE component, the second HDPE component, and / or the composition are processed under the compounding conditions disclosed herein. In some embodiments, without being bound by any particular theory, it is believed that temperatures in the range of 150° C. to 250° C. favor long chain branching over chain scission, resulting in a higher degree of long chain branching in the treated polymer and improved processability through higher melt strength. It is believed that more long chain branching occurs when the temperature decreases from 250° C. to 150° C.

[0101] Non-limiting examples of suitable free radical initiators include one or more of the group consisting of 3-hydroxy-1,1-dimethylbutyl peroxyneodecanoate, alpha-cumyl peroxyneodecanoate, 2-hydroxy-1,1-dimethylbutyl peroxyneoheptanoate, alpha-cumyl peroxyneoheptanoate, tert-amyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, di(2-ethylhexyl) peroxydicarbonate, di(n-propyl) peroxydicarbonate, di(sec-butyl) peroxydicarbonate, tert-butyl peroxyneoheptanoate, tert-amyl peroxypivalate, tert-butyl peroxypivalate, diisononanoyl peroxide, dodecanoyl peroxide, 3-hydroxy-1,1-dimethylbutyl peroxy-2-ethylhexanoate, Decanoyl peroxide, 2,T-azobis(isobutyronitrile), di(3-carboxypropionyl)peroxide, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, dibenzoyl peroxide, tert-amyl peroxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-(cis-3-carboxy)acrylate, 1,1-di(tert-amylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, OO-tert-amyl O-(2-ethylhexyl)monoperoxycarbonate, OO-tert-butyl O-isopropyl monoperoxycarbonate, OO-tert-butyl O-(2-ethylhexyl) tert-butyl peroxycarbonate, tert-butyl peroxycarbonate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butyl peroxyisononanoate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, di-tert-butyl phthalate, 2,2-di(tert-butylperoxy)butane, 2,2-di(tert-amylperoxy)propane, 4,4-di(tert-butylperoxy)butyl valerate, ethyl 3,3-di(tert-amylperoxy)butyrate, ethyl 3,3-di(tert-butylperoxy)butyrate, diisopropylbenzene peroxide, α,α'-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, di(tert-amyl)peroxy oxide, tert-butyl isopropyl peroxide, di(tert-butyl) peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne, dihexadecyl peroxydicarbonate, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxynonane, tert-butyl peroxy 2-ethylhexanoate, tert-butyl peroxy n-butyl fumarate / benzoate, ditetradecyl peroxydicarbonate, 3,3,5,7,7-pentamethyl-1,2,4-trioxepane, tert-butyl hydroperoxide, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and 1,2,4,5,7,8-hexaoxacyclononane, 3,6,9-trimethyl-3,6,9-tri(ethyl and propyl) derivatives.

[0102] -Compression molding / blow molding

[0103] Compression molding is a fast-running plastic conversion process for caps and closures that offers efficient processing with short cycle times and low energy consumption. This results in final articles with superior properties in terms of yield and dimensional consistency. The lower the conversion temperature, the less susceptible the material is to degradation.

[0104] Polyolefins that can be used in injection molding processes are also generally useful in compression molding processes, including but not limited to making lids and closures. In some embodiments, the polyolefins used in compression molding have significant shear thinning and over-proportionately low flow resistance. Such properties help maintain high yields and excellent properties, such as but not limited to ESCR, on the final article produced.

[0105] Die expansion is a common phenomenon in polyolefin extrusion processes, where the molten polymer material flow is forced through the die. Related processes include, but are not limited to, compression molding, injection molding, and blow molding. Die expansion is a phenomenon directly related to the entropy and relaxation of the polymer in the flow stream. The polymer melt flow stream has a constant rate before entering the die, and the polymer chains in the stream occupy a roughly spherical conformation, thereby maximizing entropy. Extrusion through the die causes an increase in polymer flow rate, which is partly due to the reduction of cross-sectional area in the die. The polymer chains in the polymer melt flowing through the die begin to lose their spherical shape due to the increase in flow rate. The polymer chains become more slender, and the physical entanglement between the polymer chains is reduced to a certain extent, depending on the length of time the polymer is in the die. When the polymer stream leaves the die, the remaining physical entanglement causes the polymer chains in the die stream to regain a portion of their previous shape and spherical volume, so as to return to the roughly spherical conformation that maximizes entropy.

[0106] Since polymer chain disentanglement is a kinetic process, a longer die and / or lower flow rate provides more time for disentanglement. Commercial motivations place a lower limit on the polymer flow rate through the die and an upper limit on the time the polymer can reside in the die. Therefore, polymers that are less susceptible to high polymer chain entanglement are desired.

[0107] One challenge with using polymer recyclates when compression molding caps or closures is excessive die swell. Die swell causes problems between the extrudate slicing step and transfer to the die. The polymer swells into a "mushroom-shaped" top that is challenging to transfer. This swell is a common problem with polymer recyclate streams, especially those with low I2 and / or I 21 The material properties inherent in those streams.

[0108] Since the polymer system may shrink and expand, die expansion is related to the elasticity of the polymer. When the random coil system of entangled polymer chains enters the capillary die under molten conditions, it undergoes contraction, partially relaxes in the capillary, and partially recovers at the outlet when no longer restricted by the capillary. For polyolefins, such as but not limited to polyethylene and / or polypropylene, the expansion when discharged from the capillary may be very strong. The expansion effect is critical in some polymer processes (such as but not limited to compression molding). Too much expansion may cause processing problems and defects in the molded product. ISO 11443 specifies a method for measuring die expansion by a capillary rheometer accessory.

[0109] Since polymer chain disentanglement is a kinetic process, a longer die and / or lower flow rate provides more time for disentanglement. Commercial motivations place a lower limit on the polymer flow rate through the die and an upper limit on the time the polymer can reside in the die. Therefore, polymers that are less susceptible to high polymer chain entanglement are desired.

[0110] Generally, die swell can also be reduced by using polymers that are less susceptible to such chain entanglements, such as, but not limited to, polymers with shorter average chain lengths, resulting in higher I2 and / or I 21 Polymer recycles inherently contain significant amounts of long chain polymers, thus reducing the I2 and / or I 21 . Dry blending and / or compounding with high I2 and / or I 21 Virgin polymer and polymer recycle, the low flow polyethylene is to increase the total I2 and / or I 21 However, this approach provides limited improvement in overall die swell due to the continuous presence of long molecular weight chains in the polymer recyclate component of the blend.

[0111] The polymer recyclate that has been visbroken can produce a processed polymer recyclate having a sufficiently high I2 and / or I 21 To reduce the die swell during compression molding to an acceptable level. Such processed polymer recyclates can be used in compression molding operations alone or in combination with one or more virgin polymers and / or one or more other processed polymer recyclates.

[0112] In some embodiments, the processed polyolefin recyclate useful in compression molding has a die swell less than or equal to 150%, less than or equal to 140%, less than or equal to 130%, less than or equal to 120%, less than or equal to 110%, or less than or equal to 100% (as measured by ASTM D3835 or ISO 11443).

[0113] In some embodiments, the processed polyolefin recyclate useful in compression molding has a die swell less than or equal to 200%, less than or equal to 190%, or less than or equal to 180% (as measured by ASTM D3835 or ISO 11443).

[0114] Certain embodiments

[0115] In some embodiments, the composition comprises a blend of a first HDPE component and a second HDPE component. The density of the first HDPE component is 0.955 g / cm 3 Up to 0.966g / cm 3 The second HDPE component has a density of 0.947 g / cm 3 Up to 0.954g / cm 3 in the range of 0.10 g / 10 min to 1.50 g / 10 min, and an ESCR F50 at 100% Igepal is greater than or equal to 1,000 hours.

[0116] In some embodiments, the first HDPE component is present in the blend in an amount ranging from 40 wt.% to 95 wt.%, 50 wt.% to 90 wt.%, 60 wt.% to 85 wt.%, or 70 wt.% to 80 wt.%, and the second HDPE component is present in the blend in an amount ranging from 5 wt.% to 60 wt.%, 10 wt.% to 50 wt.%, 15 wt.% to 40 wt.%, or 20 wt.% to 30 wt.%. All weight percentages are based on the combined weight of the first HDPE component and the second HDPE component.

[0117] In some embodiments of the composition, in addition to any one or more of the above limitations, the composition is further characterized in that the second HDPE component has one or more of the following: a density at least 0.003 g / cm2 less than the density of the first HDPE component. 3 , I5 is at least 0.02 g / 10 min lower than the I5 of the first HDPE component; and / or ESCR F50 in 100% Igepal is at least 100 hours longer than the ESCR F50 of the first HDPE component in 100% Igapal.

[0118] In some embodiments of the composition, in addition to any one or more of the above limitations, the composition is further characterized in that the first HDPE component has one or more of the following:

[0119] a)M n In the range of 8,000 g / mol to 20,000 g / mol or 12,000 g / mol to 16,000 g / mol;

[0120] b)M w In the range of 100,000 g / mol to 170,000 g / mol or 115,000 g / mol to 145,000 g / mol;

[0121] c) MWD in the range of 5 to 14 or 6 to 9;

[0122] d) HLMI is in the range of 35 g / 10 min to 70 g / 10 / min or 40 g / 10 min to 65 g / 10 / min; and

[0123] e) 2% flexural modulus in the range of 170,000 psi (1,172 MPa) to 230,000 psi (1,586 MPa) or 180,000 psi (1,241 MPa) to 210,000 psi (1,778 MPa).

[0124] In some embodiments of the composition, in addition to any one or more of the above limitations, the composition is further characterized in that the first HDPE component has one or more of the following:

[0125] a) Zero shear viscosity (η0) is 1.1x10 7 Up to 1.6x10 7 within the scope of

[0126] b) a bulk intrinsic viscosity ([η]) in the range of 1.40 to 1.75; and

[0127] c) Long chain branching index (LCBI) is in the range of 0.6 to 2.0.

[0128] In some embodiments of the composition, in addition to any one or more of the above limitations, the composition is further characterized in that the second HDPE component has one or more of the following:

[0129] a)M n In the range of 9,000 g / mol to 25,000 g / mol or 12,000 g / mol to 22,000 g / mol;

[0130] b)M w In the range of 150,000 g / mol to 350,000 g / mol or 200,000 g / mol to 300,000 g / mol;

[0131] c) MWD in the range of 10 to 40 or 15 to 30;

[0132] d) HLMI is in the range of 5 g / 10 min to 40 g / 10 / min or 7 g / 10 min to 30 g / 10 / min; and

[0133] e) 2% flexural modulus in the range of 120,000 psi (827 MPa) to 170,000 psi (1,172 MPa) or 136,000 psi (938 MPa) to 146,000 psi (1,007 MPa).

[0134] In some embodiments of the composition, in addition to any one or more of the above limitations, the composition is further characterized in that the second HDPE component has one or more of the following:

[0135] a) Zero shear viscosity (η0) is 1.0x10 5 Up to 1.0x10 8 within the scope of

[0136] b) a bulk intrinsic viscosity ([η]) in the range of 1.80 to 3.00; and

[0137] c) Long chain branching index (LCBI) is in the range of 0.1 to 2.0.

[0138] In some embodiments of the composition, in addition to any one or more of the above limitations, the composition is further characterized in that the blended composition has one or more of the following:

[0139] a) Density is 0.951 g / cm 3 Up to 0.962g / cm 3 or 0.956 g / cm 3 Up to 0.960g / cm 3 within the scope of

[0140] b) a melt index (I5) in the range of 0.60 g / 10 min to 2.50 g / 10 min or 0.80 g / 10 min to 1.80 g / 10 min; and

[0141] c) an environmental stress crack resistance ("ESCR") F50 in 100% Igepal in the range of 24 hours to 1,000 hours and / or an environmental stress crack resistance ("ESCR") F50 in 10% Igepal in the range of 24 hours to 84 hours.

[0142] d) M nIn the range of 10,000 g / mol to 20,000 g / mol;

[0143] e)M w In the range of 130,000 g / mol to 230,000 g / mol or 156,000 g / mol to 194,000 g / mol;

[0144] f) MWD in the range of 8 to 20 or 10 to 15;

[0145] g) HLMI is in the range of 15 g / 10 min to 45 g / 10 / min or 20 g / 10 min to 40 g / 10 / min;

[0146] h) a population polydispersity ratio (PDR) in the range of 15 to 60;

[0147] i) Zero shear viscosity (η0) is 1.0x10 6 Up to 3.0x10 7 within the scope of

[0148] j) a bulk intrinsic viscosity ([η]) in the range of 1.5 to 2.5;

[0149] k) a long chain branching index (LCBI) in the range of 0.3 to 1.3; and

[0150] 1) 2% flexural modulus is in the range of 165,000 psi (1,138 MPa) to 215,000 psi (1,482 MPa) or 175,000 psi (1,207 MPa) to 205,000 psi (1,413 MPa).

[0151] In some embodiments of the composition, in addition to any one or more of the above limitations, the first HDPE component comprises:

[0152] a) one or more HDPE homopolymers, one or more HDPE copolymers, or a combination thereof;

[0153] b) one or more HDPE recyclates, one or more virgin HDPE, or a combination thereof; or

[0154] c) one or more HDPE homopolymer recyclates, one or more HDPE copolymer recyclates, or a combination thereof.

[0155] In some embodiments of the composition, in addition to any one or more of the above limitations, the composition is further characterized in that the first HDPE component and / or the second HDPE component is treated with a peroxide prior to blending, or the blended composition is treated with a peroxide during or after blending. Such peroxide treatment of the relevant component or composition is carried out at a temperature in the range of 150° C. to 270° C., under pressure and shear conditions implemented in an extruder, sufficient to increase the melt strength of the final blended composition compared to a corresponding blended composition in which the relevant component or composition is not so treated with a peroxide.

[0156] In some embodiments of the composition, in addition to any one or more of the above limitations, the second HDPE component comprises one or more virgin HDPE homopolymers, one or more virgin HDPE copolymers, or combinations thereof.

[0157] In some embodiments of the composition, in addition to any one or more of the above limitations, the first HDPE component and the second HDPE component are melt blended at a temperature in the range of 150° C. to 270° C. In other embodiments, the blend further comprises one or more primary antioxidants, one or more secondary antioxidants, or a combination thereof. In other embodiments, the total primary antioxidant and / or total secondary antioxidant each may be present in the blend in an amount up to 1,900 ppm, up to 1,500 ppm, or up to 1,000 ppm, based on the total weight of the first HDPE component and the second HDPE component.

[0158] The following examples illustrate the present invention; however, those skilled in the art will recognize many variations within the spirit of the present invention and the scope of the claims. In order to facilitate a better understanding of the present invention, the following examples of preferred embodiments are given. The following examples should in no way be construed as limiting or defining the scope of the present invention.

[0159] Example

[0160] The following examples are included to illustrate preferred embodiments of the present invention. It will be appreciated by those skilled in the art that the techniques disclosed in the following examples represent techniques that the inventors have found to work well in the practice of the present invention and therefore can be considered to constitute preferred modes for its practice. However, in accordance with the present invention, it will be appreciated by those skilled in the art that many changes may be made to the disclosed specific embodiments without departing from the spirit and scope of the present invention and still obtaining the same or similar results.

[0161] The following examples use a commercial HDPE composition with a low melt index as a replacement for HDPE recycle feedstock and / or as a replacement for commercially available recycle feedstock.

[0162] Test Method

[0163] Environmental Stress Crack Resistance (ESCR) - Environmental stress crack resistance ("ESCR") of resins is measured according to ASTM-D 1693-01 Method B. According to this test, the susceptibility of a resin to mechanical failure by cracking is measured under conditions of constant strain and in the presence of a crack accelerator, such as soap or other wetting agents. The measurements are made on notched specimens placed in a 10% by volume solution of Igepal CO-630 (supplier Rhone-Poulec, NJ) in water maintained at 50°C. Ten specimens are evaluated for each measurement. The ESCR value of a resin is expressed as F50, the 50% failure time calculated from a probability plot.

[0164] Density is measured according to ASTM D-4703 and ASTM D-1505 / ISO-1183.

[0165] Die swell is determined herein by an in-house developed test using a Goetfert Rheograph 25 capillary rheometer. The polymer melt is extruded from the die at a temperature of 190°C with a shear rate of 525 s-1. The die swell of the extrudate is measured by a laser located 78 mm below the die bottom. The die has an orifice diameter of 1 mm and an L / D of 0.25 and an entry angle of 90°. The extrudate strand is cut before the measurement is made at a position 120 mm below the die bottom.

[0166] High Load Melt Index (“I 21 ”) is measured by ASTM D-1238-F (190°C / 21.6kg).

[0167] Shear rheology measurements were performed according to ASTM 4440-95a, which characterize the dynamic viscoelastic properties (storage modulus G', loss modulus G" and complex viscosity η * The rheological measurements were performed using a rotational rheometer (TA Instrument). A 25 mm parallel plate fixture was used. The samples were compression molded into disks (~29 mm diameter and ~1.3 mm thickness) using a hot press at 190°C. Oscillation frequency sweep experiments (from 398.1 rad / s to 0.0251 rad / s) were applied at 190°C. The applied strain amplitude was ~10% and the operating gap was set to 1 mm. A nitrogen flow was applied in the sample chamber to minimize thermal oxidation during the measurements.

[0168] Melt elasticity ("ER") is determined as discussed in R. Shroff and H. Mavridis, "New Measures of Polydispersity from Rheological Data on Polymer Melts," J. Applied Polymer Science, 57 (1995), p. 1605. See also U.S. Pat. Nos. 7,238,754, 6,171,993, and 5,534,472 (column 10, lines 20-30), the teachings of which are incorporated herein by reference. Thus, the storage modulus (G') and the loss modulus (G") are measured. The nine lowest frequency points (five points per decade) are used, and a linear equation is fit by least squares regression as log G' versus log G". ER is then calculated according to the following formula:

[0169] ER=(1.781x 10 -3 )x G',

[0170] Where G" = 5,000 dyn / cm 2 The same procedure and equations for ER calculations are used for linear polyolefins and long-chain branched polyolefins.

[0171] PDR or "overall polydispersity measure" is determined as discussed by R. Shroff and H. Mavridis in "New Measures of Polydispersity from Rheological Data on Polymer Melts," J. Applied Polymer Science 57 (1995), p. 1605, equation 27 on p. 1619, where G* ref,1 =1.95*10 4 dyn / cm 2 And log 10 (G* ref,3 / G* ref,1 ) = 2. The same procedure and equation for PDR calculation is used for both linear polyolefins and long chain branched polyolefins.

[0172] Complex viscosity at a frequency of 0.1 rad / sec and the complex viscosity at a frequency of 100 rad / sec Ratio Serves as an additional measure of the shear sensitivity and therefore of the rheological breadth or polydispersity of the polymer melt.

[0173] Melt index ("I2") is measured by ASTM D-1238-E (190°C / 2.16 kg).

[0174] Melt index ("I5") is measured by ASTM D-1238 (190°C / 5kg).

[0175] Molecular weight distribution ("MWD"), also known as M z / M w , and the molecular weight average (number average molecular weight M n , weight average molecular weight M w , z average molecular weight M z and z+1 average molecular weight M z+1 ) was determined using high temperature polymer carbon gel permeation chromatography ("GPC"), also known as size exclusion chromatography ("SEC"), equipped with a filter-based infrared detector IR5, a four-capillary differential bridge viscometer, and a Wyatt 18 angle light scattering detector. n Spectrum, M w Spectrum, M z The spectrum, MWD spectrum and short chain branching (SCB) spectrum are reported using an IR detector, while the long chain branching parameter g' is determined using a combination of a viscometer and an IR detector at 145°C. Polymer fractionation was performed using three Agilent PLgelOlexis GPC columns at 145°C based on hydrodynamic size in 1,2,4-trichlorobenzene (TCB) with 300 ppm antioxidant butylated hydroxytoluene (BHT) as the mobile phase. 16 mg of polymer was weighed in a 10 mL vial and sealed for GPC measurement. The dissolution process was done automatically in an Agilent autosampler (in 8 mL of TCB) at °160°C with continuous shaking for 1 hour. During the dissolution process, 20 μL of heptane was also injected into the vial as a mobile marker. After the dissolution process, 200 μL of the solution was injected into the GPC column. The GPC columns were calibrated based on twelve monodisperse polystyrene (PS) standards ranging from 578 g / mol to 3,510,000 g / mol (provided by PSS). The comonomer composition (or SCB profile) is reported based on different calibration profiles obtained using a relatively narrow series of polyethylenes (polyethylene with 1-hexene and 1-octene comonomers provided by polymer char, while polyethylene with 1-butene synthesized in-house) with known CH3 / 1000 total carbon values ​​determined by established solution NMR techniques. The data were analyzed using GPC one software. The long chain branching parameter g' was determined by the following equation:

[0176] g'=[η] / [η] lin

[0177] Where [η] is the average intrinsic viscosity of the polymer, which is derived by summing the slices on the GPC spectrum as follows:

[0178]

[0179] where c i is the concentration of a particular slice obtained from the IR detector, and [η] i is the intrinsic viscosity of the slice measured from the viscometer detector. [η] lin Using the Mark-Houwink equation for linear high-density polyethylene ([η] lin =∑KM i α ) is obtained from the IR detector, where M i is the viscosity average molecular weight for a reference linear polyethylene, K and α are the Mark-Houwink constants for linear polymers, which are K=0.000374, α=0.7265 for linear polyethylene, and K=0.00041, α=0.6570 for linear polypropylene.

[0180] The zero shear viscosity, η0, is determined using a fit of the Sabia equation for dynamic complex viscosity versus radian frequency as described by Shroff and Mavridis (1999) in "A long chain branching index for essentially linear polyethyl long chain branching indexfor essentially linear polyethylenes," Macromolecules, 32, 8454-8464 (collectively, Appendix B), the disclosure of which is incorporated herein by reference in its entirety.

[0181] Determine LCBI using Equation 13:

[0182]

[0183] Equation 13 and its application are described in Shroff and Mavridis (1999), "A long chain branching index for essentially linear polyethylenes," Macromolecules, 32, 8454-8464, the disclosure of which is incorporated herein by reference in its entirety.

[0184] The long chain branching frequency (characterized as the ratio of long chain branches per million carbon atoms, or LCB / 10 6 C) is determined by the method of Janzen and Colby (J. Janzen and RH Colby, "Diagnosis long chain branching in polyethylenes", Journal of Molecular Structure, Vol. 485-486, August 10, 1999, pp. 569-583), using equation (2-3) in the above reference and the constants in Table 2. Specifically, the zero shear viscosity at 190°C Determined by extrapolating the complex viscosity data via the Sabia equation, as described separately. The weight average molecular weight, Mw, is determined by GPC. Using these two parameters and the method of Janzen and Colby, the long chain branching frequency, LCB / 10 6 C can be determined numerically so that all three parameters (η0, M w and LCB / 10 6 C) satisfies equations (2-3) in the above reference. The Janzen and Colby method predicts that the zero shear viscosity of the material is similar to that of a perfectly linear polymer (LCB / 10 6 C=0) is the ratio of zero shear viscosity η0 / η 0，线性 In LCB / 10 6 The maximum value is exhibited at a certain value of C, and thus for LCB / 10 6 Each value of Cη0 / η 0，线性 , there are two levels or values ​​for which this ratio is possible. For the purposes of this calculation, LCB / 10 6 The lowest value of C is always η0 / η 0，线性 of given ratios.

[0185] raw material

[0186] The raw materials used herein are shown in Tables 1-5 below. BM1-BM3 identify and show the properties of benchmark polymers used to determine the ESCR targets to be achieved by the HDPE blends disclosed herein. FHC1 and FHC2 identify and show the properties of the first HDPE component used in the HDPE blends disclosed herein. SHC1-SHC6 identify and show the properties of the second HDPE component used in the HDPE blends disclosed herein. P1-P7 identify and show the properties of other HDPE polymers used for comparison with the HDPE blends disclosed herein.

[0187] Table 1 lists the composition types and grade numbers of the raw materials, as well as the label identifiers used in the examples of Tables 2-25 below.

[0188] Table 1

[0189] Label Composition grade BM1 HDPE <![CDATA[Petrothene LR732002 1 ]]> BM2 HDPE <![CDATA[Marlex TM HHM5502BN 3 ]]> BM3 / FHC1 HDPE <![CDATA[Petrothene LM600700 1 ]]> FHC2 HDPE Recyclate <![CDATA[EcoPrime 2 ]]> SHC1 HDPE Bimodal Copolymer <![CDATA[Alathon L4904 1 ]]> SHC2 HDPE Bimodal Copolymer Alathon L4904LS SHC3 HDPE Bimodal Copolymer <![CDATA[Alathon L4930TC 1 ]]> SHC4 HDPE Bimodal Copolymer <![CDATA[Alathon L5008HP 1 ]]> SHC5 HDPE Copolymer <![CDATA[Hyperzone HY4008 1 ]]> SHC6 HDPE Copolymer <![CDATA[Hyperzone HY54907U 1 ]]> P1 HDPE Copolymer <![CDATA[Hyperzone HY55430 1 ]]> P2 HDPE Copolymer GX5046 (Test version of P1) P3 HDPE <![CDATA[Petrothene LP5100 1 ]]> P4 HDPE Lupolen 4261AG P5 HDPE Bimodal Copolymer <![CDATA[Alathon L5440 1 ]]> P6 HDPE Bimodal Copolymer <![CDATA[Alathon L5332CP 1 ]]> P7 HDPE <![CDATA[Petrothene LT543522 1 ]]>

[0190] 1Purchased from LyondellBasell, Houston, TX

[0191] 2Purchased from Envision Plastics, Reidsville, NC

[0192] 3 Purchased from Chevron Phillips Chemical, Houston, TX

[0193] Table 2 lists the density, I2, I5, HLMI, ESCR F50, 100% Igepal and die swell for the polymers identified in Table 1.

[0194] Table 2

[0195]

[0196]

[0197] Table 3 lists the M values ​​of the polymers identified in Table 1. w 、M n 、M w / M n (MWD), M z / M w 、M z and M z+1 .

[0198] Table 3

[0199]

[0200]

[0201] Table 4 lists the ER, PDR, ETA0, ETA*100, ETA*1000 and IV of the polymers identified in Table 1.

[0202] Table 4

[0203]

[0204] Table 5 lists the bulk comonomers, bulk IV, viscosity ratio, LCBI and LCB / 10 of the polymers identified in Table 1. 6 C.

[0205] Table 5

[0206]

[0207]

[0208] Embodiment 1-36

[0209] Examples 1-36 in Tables 6-11 show parameters and properties of blends of FHC1 with one or more of SHC1, SHC2, SHC3, SHC4, SHC5, SHC6, P2, P3, P4, and P7.

[0210] Table 6 lists the weight percentages of polymers FHC1, SHC1, SHC2, SHC3, SHC4, SHC5, SHC6, P2, P3, P4, and P7 used in blend examples 1 to 36. The properties of these blends are shown in Tables 7 to 11.

[0211] Table 6

[0212]

[0213]

[0214] Table 7 lists the density, I2, I5, HLMI, ESCR F50, 100% Igepal and die swell for the example blends identified in Table 6. Figure 2 A comparison of ESCR performance from the data shown in Table 7 is shown.

[0215] Table 7

[0216]

[0217]

[0218] Table 8 lists the M of the example blends identified in Table 6. w 、M n 、M w / M n(MWD), M z / M w 、M z and M z+1 .

[0219] Table 8

[0220]

[0221]

[0222] Table 9 lists the ER, PDR, ETAO, ETA*100, ETA*1000, and IV of the example blends identified in Table 6.

[0223] Table 9

[0224]

[0225]

[0226] Table 10 lists the bulk comonomers, bulk IV, viscosity ratio, LCBI, LCB / 10 of the polymers identified in Table 6. 6 C, LCB-SHC, LCB-FHC, %FHC and linear LCB blends.

[0227] Table 10

[0228]

[0229]

[0230] Table 11 lists the ETAO of SHC, IV of SHC, ETAO of FHC, IV of FHC, ETAO, IV and LCBI of the blends for the example blends identified in Table 6.

[0231] Table 11

[0232]

[0233] Examples 42-61

[0234] Examples 42-61 in Tables 12-17 show parameters and properties of blends of FHC2 with one or more of SHC1, SHC3, SHC4, SHC5, SHC6, P2, and P7.

[0235] Table 12 lists the weight percentages of polymers FHC2, SHC1, SHC3, SHC4, SHC5, SHC6, P2, and P7 used in blend examples 42-61. The properties of these blends are shown in Tables 13-17.

[0236] Table 12

[0237]

[0238]

[0239] Table 13 lists the density, I2, I5, HLMI, ESCR F50, 100% Igepal, and die swell for the example blends identified in Table 12. Figure 3 A comparison of ESCR performance is shown in Table 13.

[0240] Table 13

[0241]

[0242]

[0243] Table 14 lists the M values ​​of the example blends identified in Table 12. w 、M n 、M w / M n (MWD), M z / M w 、M z and M z+1 .

[0244] Table 14

[0245]

[0246] Table 15 lists the ER, PDR, ETAO, ETA*100, ETA*1000, and IV of the example blends identified in Table 12.

[0247] Table 15

[0248]

[0249] Table 16 lists the bulk comonomers, bulk IV, viscosity ratio, LCBI, LCB / 10 of the polymers identified in Table 12. 6 C, LCB-SHC, LCB-FHC, %FHC and linear LCB blends.

[0250] Table 16

[0251]

[0252]

[0253] Table 17 lists the ETAO of SHC, IV of SHC, ETAO of FHC, IV of FHC, ETAO, IV and LCBI of the blends for the example blends identified in Table 12.

[0254] Table 17

[0255]

[0256]

[0257] Examples 37-41

[0258] Examples 37-41 in Tables 18-22 show the parameters and properties of blends of FHC1 and BM1 with each of SHC1, SHC3, SHC4, SHC5 and SHC6, wherein SHC1, SHC3, SHC4, SHC5 and SHC6 account for a certain amount. In these three-component blends, FHC1 and BM1 form the first HDPE component, and the density of the blend of FHC1 and BM1 is greater than 0.955 g / cm 3 .

[0259] Table 18 lists the weight percentages of polymers FHC1, SHC1, SHC3, SHC4, SHC5, SHC6, and BM1 used in blend examples 37-41. The properties of these blends are shown in Tables 19-22.

[0260] Table 18

[0261] Example FHC1 SHC1 SHC3 SHC4 SHC5 SHC6 BM1 37 25 25 -- -- -- -- 50 38 25 -- 25 -- -- -- 50 39 25 -- -- 25 -- -- 50 40 25 -- -- -- 25 -- 50 41 25 -- -- -- -- 25 50

[0262] Table 19 lists the density, I2, I5, HLMI, ESCR F50, 100% Igepal, and die swell for the example blends identified in Table 18.

[0263] Table 19

[0264]

[0265]

[0266] Table 20 lists the M values ​​of the example blends identified in Table 18. w 、M n 、M w / M n (MWD), M z / M w 、M z and M z+1 .

[0267] Table 20

[0268]

[0269] Table 21 lists the ER, PDR, ETAO, ETA*100, ETA*1000, and IV of the example blends identified in Table 18.

[0270] Table 21

[0271]

[0272] Table 22 lists the bulk comonomers, bulk IV, viscosity ratio, LCBI, LCB / 10 of the polymers identified in Table 18. 6 C, LCB-SHC, LCB-FHC, %FHC and linear LCB blends.

[0273] Table 22

[0274]

[0275]

[0276] Diameter expansion

[0277] Table 23 shows a comparison of the FHC2 and SHC1 blends disclosed herein with the benchmark polymer BM1.

[0278] Table 23

[0279]

[0280] Table 24 shows the die swell performance of Example 63 compared to the benchmark Example 62. Diameter swell and weight swell were measured on a Uniloy 350R2 single head blow molding machine. After the machine was started, virgin BM1 was run on a one gallon center fill bottle with a target of 90 g and 9.0 cm diameter swell, which was measured on the graduated handle of the mold. BM1 is a general purpose Cr-HDPE (produced using a chromium catalyst) widely used for blow molding and can be used as a processability control for this test.

[0281] The FHC2 / SHC1 blend was introduced on a BM1 control "base", mimicking a commercial type changeover. Due to differences in parison thickness and tail flash length, bottle weight changes occur. This change in bottle weight is defined as "weight swell" and is the first thing an operator will notice when changing materials. Bottle weight is then corrected back to the target value of 90g by manually adjusting the die gap.

[0282] Once the test material has returned to the target weight, the diameter expansion is measured on the graduated handle of the mold. If the target diameter expansion is larger, the tool needs to be changed to produce a wider or narrower parison. The target range for weight expansion is -20 g to +20 g, and the target range for diameter expansion is 8.0 cm to 10.0 cm. Example 63 is within the target range. This comparison is tabulated in Table 24 and graphically shown in Figure 4 middle.

[0283] Table 24

[0284]

[0285] 1Weight change in grams

[0286] 2Measured in cm on the handle

[0287] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, in addition to the ranges listed, any lower limit can be combined with any upper limit to list a range that is not explicitly listed, and the range from any lower limit can be combined with any other lower limit to list a range that is not explicitly listed, and similarly, the range from any upper limit can be combined with any other upper limit to list a range that is not explicitly listed. Additionally, even if not explicitly stated, each point or single value between its endpoints is also included in the range. Therefore, each point or single value can be combined as its own lower limit or upper limit with any other point or single value or any other lower limit or upper limit to list a range that is not explicitly listed.

[0288] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made here without departing from the spirit and scope of the present invention as defined by the appended claims. In addition, the scope of the present application is not intended to be limited to the specific embodiments of the process, machine, film structure, composition, means, method and / or step of the layer described in the specification. As will be readily understood by those of ordinary skill in the art from the disclosure of the present invention, according to the present invention, the process, machine, film structure, composition, device, method and / or step of the layer that currently exists or will be developed later to perform the function substantially the same as the corresponding embodiment described herein or to achieve substantially the same result can be used. Therefore, the appended claims are intended to include such process, machine, film structure, composition, means, method and / or step of the layer within its scope.

Claims

1. A composition comprising a blend of: a) 40 wt.% to 95 wt.% of a first high density polyethylene ("HDPE") component having: i) at 0.955 g / cm 3 Up to 0.966g / cm 3 Density within range; ii) a melt index (I5) in the range of 1.50 g / 10 min to 3.50 g / 10 min; and iii) Environmental Stress Crack Resistance ("ESCR") F50 of less than 24 hours in 100% Igepal; b) 5 to 60 wt.% of a second HDPE component having: i) at 0.947 g / cm 3 Up to 0.954g / cm 3 Density within range; ii) I5 in the range of 0.10 g / 10 min to 1.50 g / 10 min; iii) ESCR F50 greater than or equal to 1,000 hours in 100% Igepal; in, The weight percentages are based on the combined weight of the first HDPE component and the second HDPE component.

2. The composition of claim 1, wherein the first HDPE component is present in an amount ranging from 50 wt.% to 90 wt.%, and the second HDPE component is present in an amount ranging from 10 wt.% to 50 wt.%.

3. The composition of claim 2, wherein the first HDPE component is present in an amount ranging from 60 wt.% to 85 wt.%, and the second HDPE component is present in an amount ranging from 15 wt.% to 40 wt.%.

4. The composition of claim 1, wherein the second HDPE component has one or more of the following: a) has a density at least 0.003 g / cm2 less than that of the first HDPE component 3 ; b) I5 is at least 0.02 g / 10 min lower than the I5 of the first HDPE component; and c) an ESCR F50 in 100% Igepal that is at least 100 hours longer than the ESCR F50 of the first HDPE component in 100% Igapal.

5. The composition of claim 1, wherein the first HDPE component has one or more of: a) Number average molecular weight (M n ) is in the range of 8,000 g / mol to 20,000 g / mol; b) Weight average molecular weight (M w ) is in the range of 100,000 g / mol to 170,000 g / mol; c) Molecular weight distribution (MWD; M w / M n ) is in the range of 5 to 14; d) a high load melt index (HLMI) in the range of 35 g / 10 min to 70 g / 10 / min; and e) 2% flexural modulus in the range of 170,000 psi (1,172 MPa) to 230,000 psi (1,586 MPa).

6. The composition of claim 1, wherein the first HDPE component has one or more of the following: a) Zero shear viscosity (η0) is 1.1x10 7 Up to 1.6x10 7 within the scope of b) a bulk intrinsic viscosity ([η]) in the range of 1.40 to 1.75; and c) Long chain branching index (LCBI) is in the range of 0.6 to 2.

0.

7. The composition of claim 1 wherein the first HDPE component is treated with a peroxide at a temperature in the range of 150°C to 270°C under conditions of pressure and shear imposed in an extruder prior to blending with the second HDPE component, sufficient to increase the melt strength of the composition as compared to a corresponding blend of the first HDPE component and the second HDPE component wherein the first HDPE component is not so treated with a peroxide.

8. The composition of claim 1, wherein the second HDPE component has one or more of the following: a) Number average molecular weight (M n ) is in the range of 9,000 g / mol to 25,000 g / mol; b) Weight average molecular weight (M w ) is in the range of 150,000 g / mol to 350,000 g / mol; c) a molecular weight distribution (MWD) in the range of 10 to 40; d) a high load melt index (HLMI) in the range of 5 g / 10 min to 40 g / 10 / min; and e) 2% flexural modulus in the range of 120,000 psi (827 MPa) to 170,000 psi (1,172 MPa).

9. The composition of claim 1, wherein the second HDPE component has one or more of the following: a) Zero shear viscosity (η0) is 1.0x10 5 Up to 1.0x10 8 within the scope of b) a bulk intrinsic viscosity ([η]) in the range of 1.80 to 3.00; and c) Long chain branching index (LCBI) is in the range of 0.1 to 2.

0.

10. The composition of claim 1 wherein the second HDPE component is treated with a peroxide at a temperature in the range of 150°C to 270°C under conditions of pressure and shear applied in an extruder prior to blending with the first HDPE component, sufficient to increase the melt strength of the composition as compared to a corresponding blend of the first HDPE component and the second HDPE component wherein the second HDPE component is not so treated with a peroxide.

11. The composition of claim 1, wherein the blend has one or more of the following: a) Density is 0.951 g / cm 3 Up to 0.962g / cm 3 within the scope of b) a melt index (I5) in the range of 0.60 g / 10 min to 2.50 g / 10 min; c) an Environmental Stress Crack Resistance ("ESCR") F50 in 100% Igepal in the range of 24 hours to 1,000 hours and / or an Environmental Stress Crack Resistance ("ESCR") F50 in 10% Igepal in the range of 24 hours to 84 hours.

12. The composition of claim 1, wherein the blend has one or more of the following: a) Density is 0.956 g / cm 3 Up to 0.960g / cm 3 within the scope of b) a melt index (I5) in the range of 0.80 g / 10 min to 1.80 g / 10 min; c) Number average molecular weight (M n ) is in the range of 10,000 g / mol to 20,000 g / mol; d) Weight average molecular weight (M w ) is in the range of 130,000 g / mol to 230,000 g / mol; e) a molecular weight distribution (MWD) in the range of 8 to 20; f) a high load melt index (HLMI) in the range of 15 g / 10 min to 45 g / 10 / min; g) a population polydispersity ratio (PDR) in the range of 15 to 60; h) Zero shear viscosity (η0) is 1.0x10 6 Up to 3.0x10 7 within the scope of bi) a bulk intrinsic viscosity ([η]) in the range of 1.5 to 2.5; j) a long chain branching index (LCBI) in the range of 0.3 to 1.3; and k) 2% flexural modulus in the range of 165,000 psi (1,138 MPa) to 215,000 psi (1,482 MPa).

13. The composition of claim 1, wherein the blend has one or more of the following: a) Weight average molecular weight (M w ) in the range of 156,000 g / mol to 194,000 g / mol; b) a molecular weight distribution (MWD) in the range of 10 to 15; c) a high load melt index (HLMI) in the range of 20 g / 10 min to 40 g / 10 / min; and d) 2% flexural modulus in the range of 175,000 psi (1,207 MPa) to 205,000 psi (1,413 MPa).

14. The composition of claim 1, wherein the first HDPE component comprises one or more HDPE homopolymers, one or more HDPE copolymers, or combinations thereof.

15. The composition of claim 14, wherein the first HDPE component comprises one or more HDPE recyclates, one or more virgin HDPEs, or a combination thereof.

16. The composition of claim 1 wherein the first HDPE component, while or after being blended with the second HDPE component, is treated with a peroxide at a temperature in the range of 150°C to 270°C under conditions of pressure and shear applied in an extruder sufficient to increase the melt strength of the composition as compared to a corresponding blend of the first HDPE component and the second HDPE component not so treated with a peroxide.

17. The composition of claim 1, wherein the second HDPE component comprises one or more virgin HDPE homopolymers, one or more virgin HDPE copolymers, or combinations thereof.

18. The composition of claim 1, wherein the first HDPE component and the second HDPE component are melt blended at a temperature in the range of 150°C to 270°C.

19. The composition of claim 1, wherein the blend further comprises a primary antioxidant, a secondary antioxidant, or a combination thereof.

20. The composition of claim 19, wherein the primary antioxidant is present in the blend at an amount less than, or equal to, 1900 ppm and the secondary antioxidant is present in the blend at an amount less than, or equal to, 1900 ppm, wherein the ppm values ​​are based on the combined weight of the first HDPE component and the second HDPE component.

Images