High-density polyethylene composition, process for manufacturing a molded article, and molded article.

Abstract

The present invention relates to a high density polyethylene composition. The high density polyethylene composition includes a HDPE component and an LDPE component. The HDPE component has a density of from 0.945 to 0.960 g / cm3 and a melt index (I2.16) of from 0.5 to 60 dg / min. The LDPE component has a density from 0.900 to 0.930 g / cm3 and a melt index from 5 to 100 dg / 10 min. When the HDPE component and LDPE component are combined at certain concentrations, the resulting high density polyethylene composition according to embodiments disclosed herein can have unexpected and highly desirable shrinkage anisotropy and can be used in forming molded articles with desirable properties.

Description

High-density polyethylene composition, process for manufacturing a molded article, and molded article. TECHNICAL FIELD

[001] The present invention relates to the field of polyethylene compositions. BACKGROUND

[002] High-density polyethylene (HDPE) and polymer blends containing HDPE are commonly used in packaging, such as bottles, jars, and their closure systems. Packaging can be molded using known molding techniques such as injection molding, compression molding, and blow molding.

[003] Injection molding is commonly used to produce complex-shaped articles such as caps, closure systems, threaded items, and hinged items. Shrinkage anisotropy is a known problem for molded HDPE items, and especially items produced by injection molding. HDPE shrinks as it cools, but it can shrink at a higher rate in the direction it flows through the mold compared to shrinkage across the flow direction. This difference in shrinkage, called shrinkage anisotropy, distorts the shape of the molded article, causing it to warp and / or curl. In packaging, warping of the part can result in unsatisfactory performance, such as poorly fitting caps or gaskets that tear with use. Distortion becomes more likely as the size of the molded item increases.

[004] Techniques for reducing shrinkage anisotropy are known, but have disadvantages. Allowing the part to cool for longer in the mold can reduce shrinkage anisotropy, but also Petition 870250081280, dated 10 / 09 / 2025, p. 11 / 46 / 32 reduces line speeds. Consequently, polyethylene compositions that have reduced shrinkage anisotropy may be desirable. In particular, it may be desirable for the composition to retain desirable physical properties of HDPE while having reduced shrinkage anisotropy. SUMMARY

[005] A first aspect of the invention is a high-density polyethylene composition comprising: a) 70.0 to 99.9 percent by weight of a high-density polyethylene (HDPE) component having a density of 0.945 to 0.960 g / cm3 and a melt index (I2,16, abbreviated as MIh) of 0.5 to 60 dg / min., and b) a low-density polyethylene (LDPE) component having a density of 0.900 to 0.930 g / cm3 and a melt index (I2,16) of 5 to 100 dg / min., in an amount of not more than 30.0 percent by weight, and at least (a) 0.1 percent by weight, or (b) a percentage by weight equal to 0.5 x MIh, whichever is greater, wherein the high-density polyethylene composition has a density of 0.940 to 0.960 g / cm3 and a melting index (U,16) of no more than 70 dg / min, and the percentages by weight are based on the combined weight of the HDPE component and the LDPE component.

[006] A second aspect of the invention is a process for producing a molded article comprising the steps of: (1) injecting the high-density polyethylene composition according to the embodiments disclosed herein into a mold; (2) cooling the high-density polyethylene composition in the mold until it solidifies; and (3) releasing the high-density composition from the mold.

[007] A third aspect of the invention is a molded article comprising the high-density polyethylene composition in the first aspect of the invention.

[008] In some embodiments, the molded items of the present Petition 870250081280, dated 10 / 09 / 2025, p. 12 / 46 / 32: The invention may have physical properties similar to the HDPE component, but may have lower shrinkage anisotropy than the HDPE component. DETAILED DESCRIPTION

[009] The high-density polyethylene compositions of the present invention comprise an HDPE component and an LDPE component. Both the HDPE component and the LDPE component are based on different varieties of polyethylene polymers.

[0010] The term polyethylene refers to polymers comprising a major amount (>50 mol %) of units that have been derived from the ethylene monomer. This includes polyethylene homopolymers or copolymers (i.e., units derived from two or more comonomers).

[0011] The term LDPE may also be referred to as high-pressure ethylene polymer or highly branched polyethylene and should mean that the polymer is partially or fully homopolymerized or copolymerized in autoclaves or tubular reactors at pressures above 14,500 psi (100 MPa) using free radical initiators such as peroxides (see, for example, US patent 4,599,392, which is incorporated herein by reference). LDPE resins typically have a density in the range of 0.916 to 0.935 g / cm3.

[0012] The term HDPE refers to polyethylenes having densities greater than about 0.935 g / cm3 and up to about 0.980 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chromium-based catalysts or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically called metallocene catalysts), restricted geometry catalysts, phosphinimine catalysts and polyvalent aryloxyether catalysts (typically called bisphenylphenoxy catalysts).

[0013] In some embodiments, polyethylene (e.g., HDPE or LDPE) is a homopolymer free of measurable residues of Petition 870250081280, dated 10 / 09 / 2025, page 13 / 46 / 32 comonomer. In some embodiments, a polyethylene is a copolymer in which a minority of the repeating units are derived from unsaturated comonomers.

[0014] Examples of suitable comonomers used to produce polyethylene may include alpha-olefins. Suitable alpha-olefins may include those containing from 3 to 20 carbon atoms (C3-C20). For example, the alpha-olefin may be a C4-C20 alpha-olefin, a C4-C12 alpha-olefin, a C3-C10 alpha-olefin, a C3-C8 alpha-olefin, a C4-C8 alpha-olefin, or a C6-C8 alpha-olefin. In some embodiments, the alpha-olefin is selected from the group consisting of propene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, and 1-decene. In some embodiments, the alpha-olefin is selected from the group consisting of 1-butene, 1-hexene, and 1-octene. In additional embodiments, the alpha-olefin is selected from the group consisting of 1-hexene and 1-octene. HDPE component

[0015] The HDPE composition of this invention comprises an HDPE component, which comprises one or more HDPE polymers. The HDPE component has a density of 0.945 to 0.960 g / cm3 and a melting index (I2,ió) of 0.5 to 60 dg / min.

[0016] In some embodiments, the HDPE component comprises an HDPE homopolymer.

[0017] In some embodiments, the HDPE component comprises an HDPE copolymer. In some embodiments, an HDPE copolymer contains at least 95 percent by weight of repeating units derived from ethylene, or at least 96 percent by weight, or at least 97 percent by weight, or at least 98 percent by weight, or at least 99 percent by weight, with the remaining repeating units derived from unsaturated comonomers. In some embodiments, an HDPE copolymer contains at least 0.5 percent by weight of repeating units. Petition 870250081280, dated 10 / 09 / 2025, page 14 / 46 / 32 derived from comonomers, or at least 1 percent by weight, or at least 2 percent by weight, or at least 3 percent by weight, with the remaining repeating units derived from ethylene monomer. It is well known how to select comonomers, comonomer content, and molecular weight to obtain an HDPE copolymer having the desired density and melt index. In some embodiments, where the comonomer is a higher molecular weight comonomer, such as 1-octene, the comonomer content may be in the lower part of the range mentioned above. In some embodiments, where the comonomer is a lower molecular weight comonomer, such as 1-butene, the comonomer content may be in the higher part of the range mentioned above.

[0018] In some embodiments, the density of the HDPE component is at least 0.948 g / cm3 or at least 0.950 g / cm3 or at least 0.951 g / cm3. In some embodiments, the density of the HDPE component is at most 0.958 g / cm3 or at most 0.956 g / cm3 or at most 0.954 g / cm3.

[0019] In some embodiments, the melting index (I2,ió) of the HDPE component is at least 0.5 dg / min or at least 1.0 dg / min or at least 1.4 dg / min. In some embodiments, the melting index (I2,ió) of the HDPE component is at most 50 dg / min or at most 40 dg / min or at most 30 dg / min or at most 20 dg / min or at most 15 dg / min or at most 12 dg / min or at most 10 dg / min or at most 8 dg / min or at most 7 dg / min.

[0020] In some embodiments, the melt flow index to melting point ratio (I21.6 / I2.16) of the HDPE component is at least 20 or at least 30 or at least 35. In some embodiments, the melt flow index to melting point ratio (I21.6 / I2.16) of the HDPE component is at most 100 or at most 95 or at most 90. In some embodiments, the melt flow index to melting point ratio (I10 / I2.16) of the HDPE component is at least 5 or at least 10 or at least 12. In some embodiments, the ratio between melt flow index Petition 870250081280, dated 10 / 09 / 2025, page 15 / 46 / 32 fluidity and melting index (I10 / I2.16) of the HDPE component is at most 20 or at most 18 or at most 16.

[0021] In some embodiments, the number average molecular weight (Mn) of the HDPE component is at least 7000 g / mol or at least 8000 g / mol or at least 9000 g / mol. In some embodiments, the number average molecular weight (Mn) of the HDPE component is at most 16,000 g / mol or at most 15,000 g / mol or at most 14,000 g / mol.

[0022] In some embodiments, the weight-average molecular weight (Mw) of the HDPE component is at least 40000 g / mol, or at least 60000 g / mol, or at least 90000 g / mol, or at least 100000 g / mol. In some embodiments, the weight-average molecular weight (Mw) of the HDPE component is at most 350000 g / mol or at most 300000 g / mol or at most 275000 g / mol.

[0023] In some embodiments, the molecular weight distribution (Mw / Mn) of the HDPE component is at least 4 or at least 5 or at least 8 or at least 9 or at least 10. In some embodiments, the molecular weight distribution (Mw / Mn) of the HDPE component is at most 35, at most 30 or at most 25, or at most 22.

[0024] In some embodiments, the HDPE component has a unimodal molecular weight distribution. In some embodiments, the HDPE component has a bimodal molecular weight distribution. In some embodiments, the HDPE component has a multimodal molecular weight distribution.

[0025] In some embodiments, the HDPE component is selected to have properties useful for injection molded applications or for closure system applications or both.

[0026] In some embodiments, the yield strength of the HDPE component is at least 18 MPa or at least 20 MPa or at least 22 MPa or at least 23 MPa, when measured as set out in Petition 870250081280, dated 10 / 09 / 2025, p. 16 / 46 / 32 Test Methods. There is no desired maximum yield strength, but in some applications a yield strength greater than 40 MPa or 30 MPa may be unnecessary.

[0027] In some embodiments, the tensile yield strain of the HDPE component is at least 6 percent or at least 7 percent or at least 8 percent or at least 9 percent, when measured as set out in the Test Methods. In some embodiments, the tensile yield strain of the HDPE component is at most 12 percent or at most 11 percent or at most 10 percent, when measured as set out in the Test Methods.

[0028] In some embodiments, the tensile rupture strength of the HDPE component is at least 15 MPa or at least 18 MPa or at least 20 MPa or at least 22 MPa, when measured as set out in the Test Methods. In some embodiments, the tensile rupture strength is at most 40 MPa or 38 MPa or 30 MPa or 25 MPa.

[0029] In some embodiments, the elongation at break of the HDPE component is at least 500 percent or at least 600 percent or at least 650 percent, when measured as set out in the Test Methods. In some embodiments, the elongation at break of the HDPE component is at most 1200 percent or at most 1000 percent or at most 950 percent, when measured as set out in the Test Methods.

[0030] In some embodiments, the environmental stress crack resistance (ESCR) of the HDPE component is at least 100 hours or at least 250 hours or at least 500 hours or at least 800 hours or at least 1000 hours or at least 1500 hours, when measured as set out in the Test Methods. In some embodiments, the ESCR of the HDPE component is at most 3,000 hours or 2,500 hours. Petition 870250081280, dated 10 / 09 / 2025, p. 17 / 46 / 32

[0031] In some embodiments, the shrinkage anisotropy of the HDPE component is at least 1.5 or at least 2 or at least 3 or at least 4, when measured as set out in the Test Methods.

[0032] In some embodiments, the HDPE component may comprise additives in addition to the HDPE polymer(s). Additives for polyolefin polymers are described in numerous publications, such as the pamphlet: Tolinski, Additives for Polyolefins. Getting the Most out of Polypropylene, Polyethylene and TPO (Second Edition) published by the Plastics Design Library in 2015. Examples of common additives include antistatic agents, color enhancers, dyes, lubricants, fillers, pigments, primary antioxidants, secondary antioxidants, processing aids, UV stabilizers, nucleators, slip agents such as erucamide, antiblocking agents such as talc, and combinations thereof. In some applications, the additives constitute no more than 5 percent by weight of the HDPE composition, or no more than 4 percent by weight, or no more than 3 percent by weight, or no more than 2 percent by weight, or no more than 1 percent by weight.In some applications, additives constitute essentially 0 percent, by weight, of the HDPE composition.

[0033] In some embodiments, the HDPE component may comprise smaller amounts of other polymers in addition to the HDPE polymer(s), provided that the total HDPE component meets the required density and melt index. In some embodiments, the amount of other polymers in the HDPE component is a maximum of 10 percent by weight, or a maximum of 5 percent by weight, or a maximum of 2 percent by weight, or a maximum of 1 percent by weight. In some embodiments, the HDPE component contains no measurable polymers (0 percent by weight) other than the HDPE polymer(s).

[0034] HDPE polymers suitable for HDPE component Petition 870250081280, dated 10 / 09 / 2025, page 18 / 46 / 32 are commercially available, for example under the registered trademarks CONTINUUM™, UNIVAL™ and DOW™ HDPE. LDPE component

[0035] The HDPE composition of this invention comprises a low-density polyethylene (LDPE) component, which contains one or more LDPE polymers. The LDPE component in this invention has a density of 0.900 to 0.930 g / cm3 and a melt index (Iz.ió) of 5 to 100 dg / min.

[0036] In some embodiments, the LDPE component comprises an LDPE homopolymer and, in some embodiments, contains an LDPE copolymer.

[0037] In some embodiments, the density of the LDPE component is at least 0.910 g / cm3 or at least 0.915 g / cm3 or at least 0.917 g / cm3. In some embodiments, the density of the LDPE component is at most 0.928 g / cm3 or at most 0.925 g / cm3 or at most 0.924 g / cm3.

[0038] In some embodiments, the melting index (I2,ió) of the LDPE component is at least 7 dg / min or at least 10 dg / min or at least 20 dg / min or at least 30 dg / min or at least 40 dg / min or at least 50 dg / min. In some embodiments, the melting index (I2,ió) of the LDPE component is at most 80 dg / min or at most 70 dg / min or at most 60 dg / min or at most 50 dg / min or at most 40 dg / min or at most 30 dg / min or at most 20 dg / min.

[0039] In some embodiments, the number average molecular weight (Mn) of the LDPE component is at least 7000 g / mol or at least 8000 g / mol or at least 9000 g / mol. In some embodiments, the number average molecular weight (Mn) of the LDPE component is at most 12,000 g / mol or at most 10,000 g / mol or at most 9,500 g / mol.

[0040] In some embodiments, the weight-average molecular weight (Mw) of the LDPE component is at least 50000 g / mol or at least 60000 Petition 870250081280, dated 10 / 09 / 2025, p. 19 / 46 / 32 g / mol or at least 65000 g / mol. In some embodiments, the weight-average molecular weight (Mw) of the LDPE component is at most 90000 g / mol or at most 80000 g / mol or at most 75000 g / mol.

[0041] In some embodiments, the molecular weight distribution (Mw / Mn) of the LDPE component is at least 4 or at least 5 or at least 6 or at least 7. In some embodiments, the molecular weight distribution (Mw / Mn) of the LDPE component is at most 14 or at most 12 or at most 10 or at most 8.

[0042] In some embodiments, the LDPE component has higher levels of long-chain branching than the HDPE component. Long-chain branching in polymers can be characterized by the long-chain branching frequency (LCBf), measuring the long-chain branches per 1000 carbon atoms.

[0043] In some embodiments, the long chain branching frequency (LCBf) of the LDPE component is at least 0.10 or at least 0.30 or at least 0.3 or at least 0.50 or at least 0.60. In some embodiments, the long chain branching frequency (LCBf) of the LDPE component is at most 5.0 or at most 2 or at most 1.5 or at most 1.25 or at most 1.

[0044] In some embodiments, the LDPE component may comprise additives, as described above for the HDPE component.

[0045] In some embodiments, the LDPE component may comprise smaller amounts of other polymers in addition to the LDPE polymer(s), provided that the total LDPE component meets the required density and melt index and the polymers in the LDPE component are miscible with each other. In some embodiments, the amount of other polymers in the LDPE component is a maximum of 10 per Petition 870250081280, dated 10 / 09 / 2025, p. 20 / 46 / 32 percent, by weight, or at most 5 percent, by weight, or at most 2 percent, by weight, or at most 1 percent, by weight. In some embodiments, the LDPE component contains no measurable polymers (0 percent, by weight) other than the LDPE polymers.

[0046] Suitable low-density polyethylene resins are commercially available, such as DOW™ LDPE 959S. HDPE composition and use

[0047] The HDPE composition of this invention comprises both the LDPE component and the HDPE component. The concentration of the HDPE component is from 70 to 99.9 percent by weight. The concentration of the LDPE component is at most 30.0 percent by weight, and at least (a) 0.1 percent by weight, or (b) a percentage by weight equal to 0.5 times the melt index (I2,ió) of the HDPE component (abbreviated as MIh), whichever is greater. All percentages by weight are based on the combined weight of the HDPE component and the LDPE component. It is called an HDPE composition because the overall density of the composition is in the appropriate range for HDPE polymers. The HDPE composition has a density of 0.940 to 0.960 g / cm3 and a melt index (Ejó) of at most 70 dg / min.

[0048] In some embodiments, the HDPE composition contains at least 0.5 percent by weight of LDPE component, or at least 1 percent by weight, or at least 2 percent by weight, or at least 3 percent by weight, or at least 5 percent by weight, or at least 7 percent by weight, or at least 9 percent by weight. In some embodiments, the HDPE composition comprises a maximum of 25 percent by weight of LDPE component, or a maximum of 20 percent by weight, or a maximum of 15 percent by weight, or a maximum of 12 percent by weight.

[0049] In some embodiments, the percentage concentration by weight of the LDPE component in the HDPE composition is at least 0.6 x MIh or Petition 870250081280, dated 10 / 09 / 2025, p. 21 / 46 / 32 0.75 x MIh or at least 0.9 x MIh or at least 1.2 x MIh. In some embodiments, the percentage concentration by weight of the LDPE component in the HDPE composition is at most 15 x MIh or at most 10 x MIh or at most 5 x MIh.

[0050] In some embodiments, the HDPE composition comprises at least 75 percent by weight of HDPE component, or at least 80 percent by weight, or at least 85 percent by weight, or at least 88 percent by weight. In some embodiments, the HDPE composition contains a maximum of 99.5 percent by weight of HDPE component, or a maximum of 99 percent by weight, or a maximum of 98 percent by weight, or a maximum of 97 percent by weight, or a maximum of 95 percent by weight, or a maximum of 93 percent by weight, or a maximum of 91 percent by weight.

[0051] The HDPE composition may comprise additives and other polymers, as described above for the HDPE component and the LDPE component. Examples of additives and their concentration are as described above.

[0052] In some embodiments, the HDPE composition may comprise smaller amounts of other polymers besides the HDPE component and the LDPE component, provided that the overall HDPE composition meets the required density and melt index. In some embodiments, the amount of other polymers in the HDPE composition is at most 10 percent by weight, or at most 5 percent by weight, or at most 2 percent by weight, or at most 1 percent by weight. In some embodiments, the HDPE composition contains no measurable polymers (0 percent by weight) other than the HDPE component and the LDPE component.

[0053] In some embodiments, the density of the HDPE composition is at least 0.945 g / cm3, or at least 0.948 g / cm3, or at least 0.950 g / cm3, or at least 0.952 g / cm3. In some embodiments, the Petition 870250081280, dated 10 / 09 / 2025, p. 22 / 46 / 32 density of the HDPE composition is at most 0.960 g / cm3, or at most 0.955 g / cm3, or at most 0.954 g / cm3.

[0054] In some embodiments, the melting index (E,16) of the HDPE composition is at least 0.5 dg / min or at least 0.7 dg / min or at least 0.8 dg / min or at least 0.9 dg / min or at least 1 dg / min. In some embodiments, the melting index (I2,16) of the HDPE composition is at most 50 dg / min or at most 30 dg / min or at most 20 dg / min or at most 15 dg / min or at most 12 dg / min or at most 10 dg / min or at most 8 dg / min or at most 7 dg / min or at most 5 dg / min.

[0055] In some embodiments, the number average molecular weight (Mn) of the HDPE composition is at least 8000 g / mol or at least 9000 g / mol or at least 9500 g / mol. In some embodiments, the number average molecular weight (Mn) of the HDPE composition is at most 15,000 g / mol or at most 14,000 g / mol or at most 13,000 g / mol.

[0056] In some embodiments, the weight-average molecular weight (Mw) of the HDPE composition is at least 80000 g / mol or at least 90000 g / mol or at least 95000 g / mol. In some embodiments, the weight-average molecular weight (Mw) of the HDPE composition is at most 350000 g / mol or at most 300000 g / mol or at most 275000 g / mol.

[0057] In some embodiments, the molecular weight distribution (Mw / Mn) of the HDPE composition is at least 8, or at least 9, or at least 10. In some embodiments, the molecular weight distribution (Mw / Mn) of the HDPE composition is at most 30, or at most 25, or at most 22, or at most 20, or at most 15.

[0058] In some embodiments, the HDPE composition has properties useful for injection molded applications or for closure system applications or both.

[0059] In some forms, the yield strength of Petition 870250081280, dated 10 / 09 / 2025, p. 23 / 46 / 32 The HDPE composition is at least 20 MPa or at least 22 MPa or at least 24 MPa or at least 26 MPa, when measured as established in the Test Methods. In some embodiments, the tensile yield strength of the HDPE composition is less than 35 MPa or 32 MPa.

[0060] In some embodiments, the tensile yield strain of the HDPE composite is at least 6 percent or at least 7 percent or at least 8 percent or at least 9 percent, when measured as set out in the Test Methods. In some embodiments, the tensile yield strain of the HDPE composite is at most 12 percent or at most 11 percent or at most 10 percent, when measured as set out in the Test Methods.

[0061] In some embodiments, the tensile rupture strength of the HDPE composite is at least 15 MPa or at least 16 MPa or at least 17 MPa or at least 19 MPa, or at least 21 MPa, when measured as set out in the Test Methods. In some embodiments, the tensile rupture strength of the HDPE composite is no greater than 40 MPa or 38 MPa or 33 MPa.

[0062] In some embodiments, the elongation at break of the HDPE composition is at least 600 percent or at least 700 percent or at least 800 percent, when measured as set out in the Test Methods. In some embodiments, the elongation at break of the HDPE composition is at most 1000 percent or at most 900 percent, when measured as set out in the Test Methods.

[0063] In some embodiments, the environmental stress cracking resistance (ESCR) of the HDPE composition is at least 20 hours or at least 100 hours or at least 120 hours or at least 150 hours, when measured as set out in the Test Methods. In some embodiments, the ESCR is not greater than 2,000 hours, 1,000 hours or 600 hours.

[0064] In some modalities, the shrinkage anisotropy of Petition 870250081280, dated 10 / 09 / 2025, p. 24 / 46 / 32: The composition of HDPE is at most 3 or at most 2.9 or at most 2.8 or at most 2.7 or at most 2.5 or at most 2.3 or at most 2.1 or at most 1.9 or at most 1.7. Anisotropy of 1 would mean that the composition is essentially isotropic, and results below 1 would be undesirable in many cases. In some embodiments, shrinkage anisotropy below 1.3 or 1.5 may be unnecessary.

[0065] In some embodiments, the shrinkage anisotropy of the HDPE composition is at most 95 percent of the shrinkage anisotropy of the HDPE component or at most 90 percent or at most 88 percent or at most 85 percent or at most 83 percent. In some embodiments, the shrinkage anisotropy of the HDPE composition is at least 50 percent of the shrinkage anisotropy of the HDPE component or at least 60 percent or at least 70 percent.

[0066] HDPE composites can be produced by molten mixing of HDPE and LDPE components, optionally with other additives. Molten mixing equipment is commercially available and molten mixing processes are well known. In short, powders or pellets of the components are subjected to heat and shear in an extruder, mixer, or kneader or similar equipment until they melt and become homogeneously mixed. Extruders are commonly used blending equipment, and extrusion is a commonly used blending technology. In some embodiments, the melting temperature during mixing is at least 180 °C or at least 185 °C or at least 190 °C. In some embodiments, the melting temperature during mixing is at most 210 °C or at most 205 °C or at most 200 °C.

[0067] The molten HDPE composition can be manufactured to produce molded articles immediately after being mixed while still molten, such as by feeding into an extruder in Petition 870250081280, dated 10 / 09 / 2025, page 25 / 46 / 32, involves injection molding, blow molding, compression molding, or another end-use process. Alternatively, the molten HDPE composition can be transformed into pellets or another intermediate form for storage and transport, such as by extrusion, cutting, and cooling of the molten HDPE composition. Suitable pelletizing equipment is commercially available, with instructions for its use. The pellets can be remelted at a later time and used in known manufacturing processes.

[0068] The composition can be used in conventional manufacturing processes to produce molded articles, such as injection molding, compression molding, and blow molding. Each of these processes is well known and described in many publications, and the equipment to perform it is commercially available.

[0069] In an injection molding process, molten polymer is injected into a mold, cooled to form a molded part, and released from the mold. Similarly, blow-molded bottles containing a threaded opening are often produced by a hybrid process called injection stretch blow molding, in which a preform containing the threaded opening is first produced by injection molding, and then the remainder of the bottle is blow-molded from the preform.

[0070] In a compression molding process, a two-piece mold provides a cavity that has the shape of a desired molded article. The mold is heated, and an appropriate amount of molten molding compound from an extruder is loaded into the lower half of the mold. The two parts of the mold are joined under pressure. The molding compound, softened by the heat, is thus welded into a continuous mass that has the shape of the cavity. The continuous mass can be hardened by cooling under pressure in the mold. Petition 870250081280, dated 10 / 09 / 2025, page 26 / 46 / 32

[0071] Blow molding processes include extrusion blow molding, injection blow molding, and injection stretch blow molding.

[0072] In an extrusion blow molding process, the HDPE composition is melted and extruded as a hollow tube, called a parison. The parison is encased in a cooled metal mold into a shaped article, such as a bottle, container, or part. Air or a neutral gas, such as nitrogen, is then blown into the parison, inflating it into the shape of the mold. After the HDPE composition has cooled sufficiently, the mold is opened and the part is ejected.

[0073] In a blow injection molding process, the HDPE composition is melted and injected into a metal mold to form a shaped article, such as a bottle, container, or part. Air or a neutral gas, such as nitrogen, is then blown into the mold, inflating the HDPE composition into the shape of the mold. After the HDPE composition has cooled sufficiently, the mold is opened and the part is ejected.

[0074] In a blow molding and injection stretch molding process, a preform of the HDPE composition is made by injection molding. In some embodiments, the end features of the neck for the final molded item (such as threading on a bottle neck) are made in the preform. The molten preform is then placed in a mold. Air or a neutral gas, such as nitrogen, is then blown into the preform, inflating it into the shape of the mold. After the HDPE composition has cooled sufficiently, the mold is opened and the part is ejected. The preform may be blown immediately after its formation, or it may be cooled and then reheated, and blown again later.

[0075] Each of these processes produces a formatted article comprising the composition of the present invention. The formatted articles can come in a variety of shapes and sizes, from small Petition 870250081280, dated 10 / 09 / 2025, p. 27 / 46 / 32 items, such as pill bottles, up to medium items, such as beverage bottles, up to large items, such as outdoor furniture, trash cans and auto parts. In some embodiments, the composition of the present invention may be the only polymer in the molded article. In some embodiments, the molded article may contain layers or zones of different polymers to serve different purposes in the article.

[0076] In some embodiments, the formatted articles containing the HDPE composition of this invention have at least one dimension (height, width, or depth) greater than 5 cm or greater than 10 cm or greater than 15 cm or greater than 20 cm. In some embodiments, the formatted articles containing the HDPE composition of this invention have at least two dimensions at angles of 90° to each other greater than 5 cm or greater than 10 cm or greater than 15 cm or greater than 20 cm.

[0077] The compositions of this invention can be especially useful in lids and closure systems for containers. Lids and closure systems must maintain their shape to fit correctly on the container. In addition, many lids and closure systems have plastic joints. The joints must maintain their shape to open and close smoothly multiple times without tearing. The reduced shrinkage anisotropy of the compositions can help the lids, closure systems, and joints maintain their shape. Testing methods

[0078] The parameters described in this application can be measured using the following measurements:_____________________________________________ Parameter Test Density See description below Melting Index ASTM D1238 Method (at 190 °C with 2.16 kg weight) Flow Index ASTM D1238 (at 190 °C with 21.6 kg weight) Yield Strength (%), Tensile Yield Strain, Tensile Tensile Strength and Elongation at Break ASTM D638 Method (Test speed = 2 in / min) Petition 870250081280, dated 10 / 09 / 2025, page 28 / 46 / 32 Flexural modulus (Secant at 2%) ASTM D790 method (Test speed = 0.05 in / min) Environmental stress cracking resistance (ESCR) ASTM D1693 method (Condition B, 50 °C, Igepal at 10%, F50) Number average molecular weight (Mn) and weight average molecular weight (Mw) See description below Long chain branching frequency (LCBf) See description below Shrinkage anisotropy ISO 294-4: 2018 Melting Index and Flow Index

[0079] The melt index, or I2,16, for polyethylene polymers is determined according to the ASTM D1238 method at 190 °C, 2.16 kg. The high-load melt index or flow index, or I21,6, for ethylene polymers is determined according to the ASTM D1238 method at 190 °C, 21.6 kg. Measurements are recorded in dg / min. Density

[0080] Samples that are measured for density are prepared in accordance with ASTM D4703. Measurements are taken within one hour of sample pressing using ASTM D792, Method B. Gel permeation chromatography (GPC) for measuring molecular weight and long-chain branching frequency (LCBf).

[0081] The number-average molecular weight (Mn), the weight-average molecular weight (Mw), and the molecular weight distribution (Mw / Mn) are measured using gel permeation chromatography (GPC), also known as size exclusion chromatography (SEC). This technique uses an instrument containing columns filled with porous beads, an elution solvent, and a detector to separate polymer molecules of different sizes.

[0082] The molecular weight of the polymer is characterized by high-temperature gel permeation chromatography (GPC). The chromatographic system consists of a Polymer Laboratories GPC220 high-temperature chromatograph equipped with a light scattering detector. Petition 870250081280, dated 10 / 09 / 2025, page 29 / 46 A 20 / 32 2-angle laser detector from Precision Detectors (Amherst, Mass.), model 2040, and a 4-capillary differential viscometer detector, model 21 OR, available from Viscotek (Houston, Tex.). The 15-degree angle of the light scattering detector is used for calculation purposes.

[0083] Data collection is performed using GPC One Instrument Control from PolymerChar (Valencia, Spain). The system is equipped with an in-line solvent degassing device from Polymer Laboratories. The carousel compartment and the column compartment are operated at 150 °C. The columns are four 20-micron Mixed A columns from Polymer Laboratories and one 20 µm guard column. Polymer solutions are prepared in 1,2,4-trichlorobenzene (TCB). Samples were prepared at a concentration of 0.1 gram of polymer in 50 ml of solvent. The chromatographic solvent and the sample preparation solvent contained 200 ppm of butylated hydroxytoluene (BHT). Both solvent sources are sprayed with nitrogen. Polyethylene samples are gently stirred at 160 °C for 4 hours. The injection volume is 200 μL and the flow rate is 1.0 ml / minute.

[0084] The calibration of the GPC column array is performed with 21 narrow molecular weight distribution polystyrene standards. The molecular weights of the standards range from 580 to 8400000, and were arranged in 6 cocktail mixtures, with at least a decade of separation between individual molecular weights. The standard polystyrene peak molecular weights are converted to polyethylene molecular weights using the following equation (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)): where M is the molecular weight, A has a value of 0.4316, and B equals 1.0. A fifth-order polynomial is used to adapt to the respective calibration points equivalent to polyethylene. The total count Petition 870250081280, dated 10 / 09 / 2025, page 30 / 46 21 / 32 of the GPC column plates are made with Eicosane (prepared at 0.04 g in 50 milliliters of TCB and dissolved for 20 minutes with gentle stirring). Plate count and symmetry are measured in a 200 microliter injection according to the following equations: where RV is the retention volume in milliliters and the peak width is in milliliters. where RV is the retention volume in milliliters and the peak width is in milliliters. The calculations of Mn, Mw, and Mz are based on the GPC results using the RI detector and are determined from the following equations:

[0085] In order to monitor deviations over time, which may contain an elution component (caused by chromatographic changes) and a flow rate component (caused by changes in the pump), a narrow late elution peak is generally used as a marker peak. A flow rate marker is therefore established based on the flow marker of decane dissolved in the elution sample. This flow rate marker is used to linearly correct the flow rate for all samples by aligning the decane peaks. Any change in the timing of the marker peak is then assumed to be related to a linear shift. Petition 870250081280, dated 10 / 09 / 2025, page 31 / 46 / 32, alteration in both flow rate and chromatographic slope. The preferred column assembly is of 20 micron particle size and mixed porosity to adequately separate the higher molecular weight fractions appropriate for the claims. The plate count for the chromatographic system (based on eicosane, as discussed previously) should be greater than 20000 and the symmetry should be between 1.00 and 1.12.

[0086] The LCBf (in long-chain branches per 1000 carbon atoms) is calculated for each polymer sample using the following procedure: 1) The light scattering, viscosity, and concentration detectors are calibrated with NBS 1475 homopolymer polyethylene (or equivalent linear reference).

[0087] 2) Viscosity and light scattering detector compensations are corrected relative to the concentration detector, as described above in the calibration section (see references to Mourey and Balke).

[0088] 3) Baselines are subtracted from light scattering, viscometry and concentration chromatograms and integration windows are adjusted, ensuring integration of the entire low molecular weight retention volume range into the light scattering chromatogram, which is observable from the refractometer chromatogram.

[0089] 4) A linear homopolymer polyethylene Mark-Houwink reference line is established by injecting a standard with a polydispersity of at least 3.0, calculating the data file (from the calibration method above), and recording the intrinsic viscosity and molecular weight from the mass constant-corrected data for each chromatographic band.

[0090] 5) The LDPE sample of interest is analyzed, the file of Petition 870250081280, dated 10 / 09 / 2025, page 32 / 46 / 32 data (from the calibration method above) is calculated and the intrinsic viscosity and molecular weight mass constant, the data corrected for each chromatographic range are recorded. At lower molecular weights, the intrinsic viscosity and molecular weight data may need to be extrapolated so that the measured molecular weight and intrinsic viscosity asymptotically approximate a linear GPC homopolymer calibration curve.

[0091] 6) The linear reference intrinsic viscosity of the homopolymer is shifted at each point (i) by the following factor: IVi = IVi * 0.946, where IV is the intrinsic viscosity.

[0092] 7) The linear reference molecular weight of the homopolymer is shifted by the following factor: MW = MW * 1.57, where MW is the molecular weight.

[0093] 8) The g' in each chromatographic band is calculated according to the following equation: g' = (IV(LDPE) / IV(linear reference)), at the same molecular weight. The IV (linear reference) was calculated from a fifth-order polynomial fit of the reference Mark-Houwink plot, where IV (linear reference) is the intrinsic viscosity of the linear homopolymer polyethylene reference (adding an amount of SCB (short chain branching) to account for slander via Equations 5) and 6) at the same molecular weight (MW)). The IV relationship is assumed to be between molecular weights less than 3500 g / mol to account for natural scattering in the light scattering data.

[0094] 9) The number of branches in each data range was calculated according to Equation 12 (as described in Zimm, Stockmayer J. Chem. Phys. 17, 1301 (1949)): Petition 870250081280, dated 10 / 09 / 2025, page 33 / 46 / 32 (12)

[0095] 10) The average LCB quantity was calculated in all ranges (i), according to Equation 13: LCBf=Σ'μ=3500 (w. * 14000Cí) (13) Examples

[0096] A bimodal HDPE resin (bimodal HDPE 1) is produced using a catalytic system including a procatalyst, UCAT™ J (commercially available from Univation Technologies, LLC, Houston, TX, USA), and a cocatalyst, triethylaluminum (TEAL), in a gas-phase polymerization process. The UCAT™ J catalyst is partially activated by contact at room temperature with an appropriate amount of a 50% tri-n-hexyl aluminum (TNHA) mineral oil solution. Fluid catalyst paste is added to a mixing vessel. During stirring, a 50% tri-n-hexyl aluminum (TNHA) mineral oil solution is added at a ratio of 0.17 mol of TNHA to mol of residual tetrahydrofuran (THF) in the catalyst and stirred for at least 1 hour before use.

[0097] Ethylene and 1-hexene are copolymerized in two fluidized bed reactors.Each polymerization is conducted continuously, after equilibrium is reached, under the respective conditions, as shown below in Tables 1. Polymerization is initiated in the first reactor by continuously feeding the catalyst and cocatalyst (trialkyl aluminum, specifically triethyl aluminum or TEAL) into a fluidized bed of polyethylene granules, along with ethylene, hydrogen, and 1-hexene. The resulting polymer, mixed with the active catalyst, is removed from the first reactor and transferred to the second reactor, using gas from the second reactor as a transfer medium. The second reactor also contains a fluidized bed. Petition 870250081280, dated 10 / 09 / 2025, page 34 / 46 / 32 fluidized polyethylene granules. Ethylene, hydrogen, and hexene are introduced into the second reactor, where the gases come into contact with the polymer and catalyst from the first reactor. Inert gases, nitrogen and isopentane, make up the remaining pressure in both the first and second reactors. In the second reactor, the cocatalyst (TEAL) is reintroduced. The final product mixture is continuously removed. Table 1 lists the polymerization conditions. Table 1 - HDPE 1 bimodal reaction conditions_____________________ 1st Reactor Temperature °C 85.0 Pressure psig 345 Part C2. Pressure psi 31.9 Molar ratio of H2 / C2 mol / mol 0.077 Molar ratio of C6 / C2 mol / mol 0.101 % of isopentane % by mol 3.1 Catalyst type UCAT™ J Catalyst feed rate cm3 / h 14.2 Cocatalyst type TEAL Cocatalyst concentration %, by weight, in isopentane 2.5% Cocat. Feed rate cm3 / h 748 Production rate lb / h 32.3 Bed weight kg (lbs) 88.5 Division (% of HMW) % 41.5% Flow rate, I21 dg / min 5.39 Density g / cm3 0.9263 2nd reactor Temperature in the 2nd reactor °C 105 Pressure in the 2nd reactor psig 393 C2 component in the second reactor Pressure psi 103 Molar ratio H2 / C2 in the 2nd reactor mol / mol 1.8 Molar ratio C6 / C2 in the 2nd reactor mol / mol 0.001 Isopentane in the 2nd reactor % by mol 0.30 Cocatalyst type in the 2nd reactor TEAL Cocatalyst concentration in the 2nd reactor %, by weight, in isopentane 2.5% 2nd cocat. Feed rate cm3 / h 150 Production rate in the 2nd reactor lb / h 45.6 Bed weight in the 2nd reactor kg (pounds) 146 Petition 870250081280, dated 10 / 09 / 2025, pages 35 / 46 / 32

[0098] The product (HDPE Bimodal 1) is combined with additives (1000 ppm calcium stearate and 1500 ppm Irgafos™ 168) and fed into a continuous mixer (Kobe Steel, Ltd. LCM-100 continuous mixer), which is directly coupled to a gear pump and is equipped with a molten material filtration device and an underwater pelletizing system. It has the properties shown in Table 2.

[0099] In addition, the commercial HDPE and LDPE resins listed in Table 2 are obtained. Some of the commercial resins may contain additives. Petition 870250081280, dated 10 / 09 / 2025, page 36 / 46 / 32 Table 2 Shrinkage anisotropy 1.82 2.94 2.64 1.19 LCBf OOO 0.72 ESCR 309 364 176 V Along. For breakage (%) O o 00 069 006 00 ' / Ί Tensile rupture stress (MPa) 22.0 22.1 37.9 6.21 Tensile yield strength (%) 8.8 o> O r-> Yield limit stress (MPa) 26.7 28.3 23.4 0'H Density (g / cm3) 0.955 0.955 0.952 0.923 Melting index (I2,tó) (dg / min) 3.8 1.5 V ' / Ί ' / Ί Resin name HDPE Bimodal 1 CONTINUUM™ DMDC 1250 UNIVAL™ DMDA 6143 DOW™ LDPE 959S Type HDPE Bimodal HDPE Bimodal HDPE Unimodal LDPE H1 H2 H3 L1 Petition 870250081280, dated 10 / 09 / 2025, pages 37 / 46 / 32

[00100] HDPE and LDPE resins are mixed in an extruder and pelletized in the proportions shown in Table 4, to produce the HDPE compositions shown in Table 4. (Compositions EI1 to EI5 are examples of the invention. Compositions EC1 to EC6 are comparative examples.)

[00101] Suitable quantities of HDPE (powder or pellet) are weighed, manually mixed, and placed into a K-tron T-20 single-screw polymer feeder. The feeder feeds the blend into a Coperion ZSK 25 mm twin-screw extruder (8 cylinders, 44 L / D, electric heating and water cooling) with a gearbox ratio of 1:89 and a rotation speed of up to 1200 RPM. The maximum torque for this line is 106 Nm. The cylinder length is 1125 mm, with 11 cylinders comprising the entire process section. The internal diameter of the extruder cylinder is 25 mm. Nitrogen impregnation (9.5 SCFH) is maintained in the feed throat throughout the compounding process. The screw design used for this project is the ZSK-25 lightweight screw. The material residence time is controlled by the screw design, feed rate of 25 l / h, screw RPM was 300. No oil is injected. No vacuum is used. A buffer is added to the 8th cylinder.No vents are used.

[00102] The composite materials are extruded through a 3 mm 4-hole die into a 6-foot-long ice water bath. The cords are then passed through a Huestis air block to remove excess water. After the cords are cooled and dried, they are pelletized using the Conair cord pelletizer. The chopped pellets are dried overnight.

[00103] To evaluate the shrinkage anisotropy property, the molten resin is injection molded to form sample plates following the standards of ISO 294-4: 2018 using the conditions provided in Petition 870250081280, dated 10 / 09 / 2025, pp. 38 / 46 29 / 32 Table 3. The injection molding machine is a Toy injection molding machine, SEI 10. Table 3: Processing conditions used in the door injection molding machine Melting temperature (°F) 428 Injection speed (cmVs) 36 Retention time (s) 14 Retention pressure (psi) 7750 Mold temperature (°F) 80 Cooling time (s) 10

[00104] Sample plates are aged for 72 hours at a constant temperature and constant humidity atmosphere (73°F and 50% relative humidity). Total shrinkage is measured in directions parallel to the melt flow and perpendicular to the melt flow direction. Plate dimensions are measured in each direction using the optical method, measuring the average length between the edges, leaving 3.175 mm at the corners. After obtaining the plate dimensions, the total shrinkage in both directions is calculated using the equations provided in the ISO 294-4 Standard 2018. Shrinkage anisotropy is calculated as follows:

[00105] In addition, the melt index and density of each HDPE composition are measured. The results are recorded in Table 4 and Table 5. As shown by the examples, the present invention reveals HDPE compositions having unexpectedly low shrinkage anisotropy. The HDPE compositions comprise an HDPE and LDPE component. The examples demonstrate that simply mixing a low-shrinkage anisotropy HDPE with a high-shrinkage anisotropy LDPE does not result in desirable shrinkage anisotropy. For example, the mixture of H3 and LI in a weight ratio of 99:1 (EC 5) and 90:10 (EC 6) exhibits unexpectedly higher shrinkage anisotropy. Petition 870250081280, dated 10 / 09 / 2025, p. 39 / 46 / 32 high than H3 (EC 6) or L1 (EC 7). In contrast, the mixture of H1 and H2 with L1 (e.g., EI 1, EI 2, and EI 3) results in HDPE compositions with desirable shrinkage anisotropy. Furthermore, the mixture of H2 and L1 at 99:1 (EI 1) exhibits less shrinkage anisotropy than H2. However, the mixture of H1 and L1 at the same ratio (EC 2) exhibits higher shrinkage anisotropy than H1. Petition 870250081280, dated 10 / 09 / 2025, pp. 40 / 46 / 32 Ía 4 Properties of the ESCR composition (F50, h) 378 162 364 101 162 309 144 144 176 V Elongation at break (%) 790 850 069 810 820 O 00 930 850 006 00 ' / Ί Breaking stress (MPa) 22.6 22.1 22.1 17.2 20.6 22.0 30.2 29.7 37.9 6.21 % yield strain oo O 9.4 8.8 8.8 9.6 00 O η Yield strength (MPa) 27.6 25.4 28.3 25.0 25.9 26.7 25.6 27.1 23.4 0'Π Shrinkage anisotropy 2.76 2.41 2.94 1.61 1.84 1.82 2.99 2.96 2.64 1.19 Density (g / cm3) 0.954 0.953 0.955 0.952 0.955 0.955 0.951 0.954 0.952 0.923 I 2.16 (dg / min) 1.47 1.81 1.50 4.44 3.84 3.75 VV 0.3 50.32 LDPE Conc. min. of LDPE (%) 0.75 0.75 0.75 1.88 1.88 1.88 <0.50 <0.50 <0.50 NA % Ο Ο Ο Ο Ο Ο 100 LDPE L1 L1 L1 L1 1 L1 L1 1 L1 HDPE % 66 06 100 06 66 100 06 66 100 I 2.16 (dg / min) ιτγ ιτγ ιτγ 3.75 3.75 3.75 0.3 0.3 0.3 HDPE H2 H2 H2 H1 H1 H1 H3 H3 H3 [abe] IE 1 IE 2 CE 1 IE 3 CE2 CE3 CE4 CE5 CE6 EC 7 Petition 870250081280, dated 10 / 09 / 2025, pp. 41 / 46 / 32 Table 5 Properties of additional composition LCBf O ooo' Os oo o' O 0,024 0,013 LLCO 0,72 Mw / M n 11,10 10,84 12,50 9,71 9,91 10,40 20,47 21,20 20,73 7,32 Mn (g / mol) 587.781 594.875 683.970 615.784 617.676 716.202 2.885.969 2.900.566 3.469.537 314.520 Mw (g / mol) 111.847 109.915 122.102 95.100 O oo Os 000 101 254.000 269.000 275.866 67.563 Mn (g / mol) Δ60ΌΙ 10.144 9.766 9.800 9.760 9.620 12.400 12.700 13.309 9.225 Modulo de flexão (Secante a 2 %, 0,05 pol / min) (MPa) 894 793 982 818 850 880 735 799 600 1 NA I 21 (dg / min) 106 123 100 278 110 (dg / min) 21,5 25,7 62,9 55,7 53,5 3,06 2,87 I 2.16 (dg / min) 1,47 1,81 1,50 4,44 3,84 3,75 VV 0,3 50,32 LDPE Conc. min. de LDPE (% em peso) 0,75 0,75 0,75 1,88 1,88 1,88 <0,50 <0,50 <0,50 NA % em peso OOOOOO 100 LDP E L1 L1 L1 L1 1 L1 L1 1 L1 % em peso 66 06 100 06 66 100 06 66 100 HDPE I 2.16 (dg / min ) ιτγ ιτγ ιτγ 3,75 3,75 3,75 0,3 0,3 0,3 HD PE H2 H2 H2 H1 H1 H1 H3 H3 H3 IE 1 IE 2 CE 1 IE 3 CE 2 CE 3 CE 4 CE 5 CE 6 CE 7

Claims

1. High-density polyethylene composition, characterized in that it comprises: a) 70.0 to 99.9 percent by weight of high-density polyethylene (HDPE) component having a density of 0.945 to 0.960 g / cm3 and a melt index (E,16, abbreviated as MIh) of 0.5 to 60 dg / min, and b) a low-density polyethylene (LDPE) component having a density of 0.900 to 0.930 g / cm3 and a melt index (I2,16) of 5 to 100 dg / min, in a concentration of not more than 30.0 percent by weight, and at least (a) 0.1 percent by weight, or (b) a percentage by weight equal to 0.5 x MIh, whichever is greater, wherein the high-density polyethylene composition has a density of 0.940 to 0.960 g / cm3 and a melting index (E,16) of no more than 70 dg / min, wherein the percentages by weight are based on the combined weight of the HDPE component and the LDPE component.

2. High-density polyethylene composition according to claim 1, the high-density polyethylene composition being characterized in that it has a melt index (I2,ió) of 0.7 to 10 dg / min.

3. High-density polyethylene composition according to claim 1, the high-density polyethylene composition being characterized in that it has a melt index (I2,ió) of 1 to 7 dg / min.

4. High-density polyethylene composition according to any of the preceding claims, characterized in that the HDPE component has a melt index (E,i6) of no more than 12 dg / min.

5. High-density polyethylene composition according to any one of claims 1 to 3, characterized in that the HDPE component has a melt index (E,i6) of no more than 8 dg / min.

6. High-density polyethylene composition according to Petition 870250081280, dated 10 / 09 / 2025, page 43 / 46 2 / 3 any of the previous claims, characterized in that the LDPE component has a density of 0.915 g / cm3 to 0.928 g / cm3.

7. High-density polyethylene composition according to any of the preceding claims, characterized in that the LDPE component has a melt index (I2,ió) of 20 dg / min to 80 dg / min.

8. High-density polyethylene composition according to any of the preceding claims, characterized in that the LDPE component has an average short-chain branching frequency that is at least 0.30 per 1000 carbons.

9. High-density polyethylene composition according to any of the preceding claims, characterized in that the weight percentage of the LDPE component in the high-density polyethylene composition is at least 0.60 x 10⁻¹⁵ mh, based on the combined weight of the HDPE component and the LDPE component.

10. High-density polyethylene composition according to any of the preceding claims, the high-density polyethylene composition being characterized in that it comprises 80 to 99 percent by weight of the HDPE component and 2 to 20 percent by weight of the LDPE component, based on the combined weight of the HDPE component and the LDPE component.

11. High-density polyethylene composition according to any of the preceding claims, the high-density polyethylene composition being characterized in that it has a density of 0.948 g / cm3 to 0.955 g / cm3.

12. High-density polyethylene composition according to any of the preceding claims, the high-density polyethylene composition being characterized in that it has a shrinkage anisotropy that is no more than 90 percent of the shrinkage anisotropy of the HDPE component. Petition 870250081280, dated 10 / 09 / 2025, pp. 44 / 46 3 / 3 13. High-density polyethylene composition according to any of the preceding claims, the high-density polyethylene composition being characterized in that it has a yield strength of at least 24 MPa and an environmental stress cracking resistance of at least 100 hours, when measured according to the Test Methods mentioned in the present invention.

14. Process for manufacturing a molded article, characterized in that it comprises the steps of: (1) injecting the high-density polyethylene composition as defined in any of claims 1 to 13 into a mold; (2) cooling the high-density polyethylene composition in the mold until it solidifies; and (3) releasing the high-density polyethylene composition from the mold.

15. Molded article, characterized in that it comprises a high-density polyethylene composition as defined in any one of claims 1 to 13.