Rotomolded bimodal polyethylene compositions with low relative elasticity, rotomolded part and process for the production of hollow polyolefin articles.

Abstract

ROTOMOLDING COMPOSITIONS WITH LOW RELATIVE ELASTICITY. High-density polyethylene compositions with a high flow index and bimodal composition provide an excellent combination of processability, stiffness, and ductility in rotomolded articles. The compositions have a low relative elasticity (GG, measured at 0.05 rad / s) of less than 0.03.

Description

1 / 39 “ROTOMOLDING BIMODAL POLYETHYLENE COMPOSITIONS WITH LOW RELATIVE ELASTICITY, ROTOMOLDED PART AND PROCESS FOR THE PRODUCTION OF HOLLOW POLYOLEFIN ARTICLES” TECHNICAL FIELD

[001] This disclosure refers to high-density polyethylene compositions for use in rotomolded articles. The compositions have high stiffness and ductility. The compositions also have a high melt flow index, which facilitates molding, especially for parts with complex shapes and geometries. The compositions have a low relative elasticity (G' / G''). FUNDAMENTALS OF THE TECHNIQUE

[002] There are several different considerations for manufacturing a resin suitable for use in rotomolding manufacturing, examples not limited to: the resin needs to be capable of producing at commercially acceptable production rates; the resin needs to be suitable for use in the rotomolding process (e.g., have a suitable sintering temperature and a suitable cooling rate to be removed from the mold); and the final rotomolded parts must have properties suitable for the end-use applications.

[003] U.S. Patents Nos. 5,382,630 and 5,382,631, granted on January 17, 1995 to Stehling, assigned to Exxon, teach bimodal resins with superior physical properties. The patent requires that the mixture have two or more components, each with a polydispersity (Mw / Mn) less than 3, and the mixture with a polydispersity greater than 3, and no component in the mixture with a relatively higher molecular weight and a lower comonomer content (i.e., the comonomer incorporation is reversed).

[004] U.S. Patent No. 6,969,741, granted November 29, 2005 to Lustiger et al., assigned to ExxonMobil, teaches a suitable polyethylene mixture. Petition 870240016554, dated 28 / 02 / 2024, page 9 / 52 2 / 39 for rotomolding. The patent teaches that the difference in density of each component is not less than 0.030 g / cm3. The difference in the densities of the component polymers in the present composition is less than 0.030 g / cm3.

[005] U.S. Patent No. 8,486,323 granted on July 16, 2013 in the name of Davis, assigned to Dow Global Technologies Inc., teaches polymer blends used in spin-molded articles with high impact resistance. The blends have a residual unsaturation of less than 0.06 per 1000 carbon atoms. SUMMARY OF THE INVENTION

[006] One embodiment of the invention provides: a bimodal polyethylene composition with 1) a molecular weight distribution, Mw / Mn, of 2.3 to 5.5; 2) a density of 0.940 to 0.957 g / cm3; 3) a melting index, I2, as measured by ASTM D1238 at 190 °C using a 2.16 kg charge of 4 to 10 grams for 10 minutes; and 4) a relative elasticity, G' / G'' when measured at 190 °C and 0.05 rad / second less than 0.03 rad / s, wherein the said bimodal polyethylene composition comprises: A. 10 to 70% by weight of a first ethylene copolymer with: Ai A melting index, I2, as measured by ASTM D1238 at 190 °C using a 2.16 kg charge of 0.4 to 5 grams for 10 minutes; A.ii. A molecular weight distribution, Mw / Mn, of 1.8 to 3.0; and A.iii. A density of 0.920 to 0.950 g / cm3; B. 90 to 30% by weight of a second ethylene copolymer with: Bi A melting index, I2, as measured by ASTM D1238 at 190 °C using a 2.16 kg charge of 4 to 1500 grams for 10 minutes; B.ii. A molecular weight distribution, Mw / Mn, of 2.3 to 6.0; and Petition 870240016554, dated 28 / 02 / 2024, page 10 / 52 3 / 39 B.iii. A density that is greater than the density of the aforementioned first ethylene copolymer, but less than 0.967 g / cm3; provided that the density of said first ethylene copolymer is less than the density of said second ethylene copolymer by a value of 0.010 to 0.035 g / cm3.

[007] Another embodiment provides a process for the production of hollow polyolefin articles, comprising loading the bimodal polyethylene composition, according to claim 1, into a mold, heating this mold in an oven above 280 °C, so that the stabilized polyolefin melts, rotating the mold around at least 2 axes, the plastic material spreading to the walls, cooling the mold while still rotating, opening it and removing the resulting hollow article.

[008] Another embodiment provides a process for manufacturing a bimodal polyethylene composition, as described above, comprising feeding ethylene and one or more C4-8 comonomers to two sequential solution phase reactors, in the presence of a single-site catalyst comprising a phosphinimine ligand together with one or more activators in the first reactor and a Ziegler Natta (ZN) catalyst in the second reactor. In one embodiment, the single catalyst is defined by the formula: (PI)m I (L)n — M — (Y)p where M is selected from the group consisting of Ti, Zr and Hf; PI is a phosphinimine ligand of the formula: Petition 870240016554, dated 28 / 02 / 2024, p. 11 / 52 4 / 39 R21 R21— P = N — / R21 where each R21 is independently selected from the group consisting of a hydrogen atom; a halogen atom; hydrocarbyl radicals, typically C1-10, which are unsubstituted or additionally substituted by a halogen atom; C1-8 alkoxy radicals; C6-10 aryl or aryloxy radicals; amido radicals; silyl radicals of the formula: -Sl-(R22)3 wherein each R22 is independently selected from the group consisting of hydrogen, a C1-8 alkyl or alkoxy radical and C610 aryl or aryloxy radicals; and a germanyl radical of the formula: --Ge--(R22)3 where R22 is defined above; L is a monoanionic cyclopentadienyl type ligand selected independently from the group consisting of cyclopentadienyl type ligands, Y is independently selected from the group consisting of activatable ligands; m is 1 or 2; n is 0 or 1; p is an integer and the sum of m + n + p equals the valence state of M.

[009] A further embodiment provides a rotomolded part consisting essentially of the above bimodal polyethylene composition. In another embodiment, rotomolded parts made of the above bimodal polyethylene composition exhibit ductile failure. BRIEF DESCRIPTION OF THE DRAWINGS Petition 870240016554, dated 28 / 02 / 2024, page 12 / 52 5 / 39

[010] Figure 1 shows the deconvolution of Example 1. The experimentally measured GPC chromatogram was deconvolved into a first and a second ethylene interpolymer based on the predictions of the kinetic model.

[011] Figure 2 shows the deconvolution of Example 2. The experimentally measured GPC chromatogram was deconvolved into a first and a second ethylene interpolymer (based on the predictions of the kinetic model).

[012] Figure 3 is a graph of the molecular weight distribution obtained by gel permeation chromatography (GPC) of the resin from examples 1, 2, 3 and 4.

[013] Figure 4 is a graph of the molecular weight distribution obtained by gel permeation chromatography (GPC) of the resin from examples 1, 8, 9 and 10.

[014] Figure 5 is a graph of the molecular weight distribution obtained by gel permeation chromatography (GPC) and the short chain branching distribution determined from GPC-FTIR of the resin from examples 3 and 4.

[015] Figure 6 is a graph of the molecular weight distribution obtained by gel permeation chromatography (GPC) and the short chain branching distribution determined from GPC-FTIR of the resin from examples 5, 6, 8 and 9. DESCRIPTION OF THE METHODS OF IMPLEMENTATION Number ranges

[016] Except in operational examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, etc., used in the descriptive report and claims should be understood as modified in all cases by the term “about”. Consequently, unless otherwise indicated, the numerical parameters set forth in the following descriptive report and appended claims are approximations that may vary depending on the desired properties of the disclosed embodiments. At a minimum, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each parameter Petition 870240016554, dated 28 / 02 / 2024, page 13 / 52 The numerical value 6 / 39 should at least be interpreted in light of the reported number of significant digits and by applying common rounding techniques.

[017] Although the numerical ranges and parameters that establish the broad scope of this disclosure are approximations, the numerical values ​​established in the specific examples are reported to the greatest extent possible. Any numerical values, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective test measurements.

[018] Furthermore, it should be understood that any numerical range cited in this report is intended to include all subranges contained therein. For example, a range of “1 to 10” is intended to include all subranges between and including the minimum recited value of 1 and the maximum recited value of 10; that is, with a minimum value equal to or greater than 1 and a maximum value equal to or less than 10. As the disclosed numerical ranges are continuous, they include all values ​​between the minimum and maximum values. Unless expressly stated otherwise, the various numerical ranges specified in this request are approximations.

[019] All composition ranges expressed in this report are limited in total and do not exceed 100 percent (percentage by volume or percentage by weight) in practice. Where multiple components may be present in a composition, the sum of the maximum quantities of each component may exceed 100 percent, with the understanding that, and as those skilled in the art readily understand, the quantities of the components actually used will conform to the maximum of 100 percent.

[020] The compositions of the present disclosure are bimodal polyethylene and can be deconvolved into two distinct components. This is usually demonstrated by the presence of a “bump” on the right-hand side of a gel permeation chromatography (GPC) curve (Figure 1). In the present case, there is a Petition 870240016554, dated 28 / 02 / 2024, page 14 / 52 7 / 39 small bump on the right side of the GPC curve, as shown in Figure 2, indicating a small amount of a lower molecular weight, low-density component.

[021] The high molecular weight component has a melting index of 0.4 to 5 and is present in an amount of about 10 to about 70% by weight of the whole composition, preferably about 15 to about 50% by weight. The low molecular weight component is present in corresponding amounts of about 90 to about 30% by weight of the whole composition, preferably about 85 to about 50% by weight based on the weight of the whole composition.

[022] In one embodiment, the higher molecular weight component has a weighted average molecular weight (Mw) of about 70,000 to about 150,000, as determined using gel permeation chromatography (GPC). The higher molecular weight component has a polydispersity (Mw / Mn: weighted average molecular weight / number average molecular weight)) of 1.8 to 3.0. The melting index, I2, of the overall composition is about 4 to 10.

[023] The higher molecular weight component has a lower density than the lower molecular weight component. The density of the higher molecular weight component in the composition can vary from about 0.920 to about 0.950 g / cm3. The density of the component, or of any other component or of the total composition, is a function of the degree of comonomer incorporation. The higher molecular weight component preferably does not have any long chain branching.

[024] The lowest molecular weight component has a melting index of 4 to 1,500. In one embodiment, the Mw is about 28,000 to about 72,000, as determined using gel permeation chromatography (GPC), and a polydispersity (Mw / Mn) of 2.3 to 5.0. Petition 870240016554, dated 28 / 02 / 2024, page 15 / 52 8 / 39

[025] The component with the lower molecular weight has a density that is 0.010 to 0.030 g / cm3 higher than the component with the higher molecular weight.

[026] The catalysts used to produce bimodal polyethylene compositions preferably do not produce long-chain branching.

[027] The general properties of bimodal polyethylene compositions include the following: density of about 0.940 to about 0.957 g / cm3; melt index under a load of 2.16 kg (12) at a temperature of 190 °C, as determined by ASTM 1238, of about 4 to about 10; and a relative elasticity G' / G'', when measured at 190 and 0.05 rad / second, less than 0.03 (especially from 0.01 to 0.03).

[028] In one embodiment, the total polyethylene compositions have a comonomer content of less than 1.2 mol%, as measured by Fourier Transform Infrared (FTIR).

[029] The polymer can be made using a solution polymerization technique. In the solution polymerization of ethylene with one or more comonomers, non-limiting examples of comonomers include C3-8 α-olefins; in some cases, 1-hexene or 1-octene are preferred, or; in other cases, 1-octene is preferred. The monomers are typically dissolved in an inert hydrocarbon solvent, typically a C5-12 hydrocarbon, which may be unsubstituted or substituted with a C1-4 alkyl group, such as pentane, methylpentane, hexane, heptane, octane, cyclohexane, methylcyclohexane, and hydrogenated naphtha. An example of a suitable solvent that is commercially available is “Isopar E” (C8-12 aliphatic solvent, Exxon Chemical Co.).

[030] Catalysts and activators are also dissolved in the solvent or suspended in a diluent miscible with the solvent under the reaction conditions. CATALYSTS Petition 870240016554, dated 28 / 02 / 2024, page 16 / 52 9 / 39

[031] In one embodiment, the single-site catalyst is a compound of the formula (PI)m I (L)n — M — (Y)p where M is selected from the group consisting of Ti, Zr and Hf; PI is a phosphinimine ligand of the formula: R21 R21— P = N — / R21 where each R21 is independently selected from the group consisting of a hydrogen atom; a halogen atom; hydrocarbyl radicals, typically C1-10, which are either unsubstituted or substituted by a halogen atom; C1-8 alkoxy radicals; C6-10 aryl or aryloxy radicals; amido radicals; silyl radicals of the formula: --Si--(R22)3 wherein each R22 is independently selected from the group consisting of hydrogen, a C1-8 alkyl or alkoxy radical and C610 aryl or aryloxy radicals; and a germanyl radical of the formula: --Ge--(R22)3 where R22 is defined above; L is a monoanionic cyclopentadienyl ligand independently selected from the group consisting of cyclopentadienyl ligands, Y is independently selected from the group consisting of activatable ligands; m is 1 or 2; n is 0 or 1; p is an integer and the sum of m + n + p equals the valence state of M. Petition 870240016554, dated 28 / 02 / 2024, p. 17 / 52 10 / 39

[032] Suitable phosphinimines are those in which each R21 is a hydrocarbyl radical, preferably a C1-6 hydrocarbyl radical, more preferably a C1-4 hydrocarbyl radical.

[033] The term “cyclopentadienyl” refers to a 5-membered carbon ring with a delocalized bond within the ring and typically being linked to the active catalyst site, usually a group 4(M) metal via 5 eta bonds.The cyclopentadienyl ligand may be unsubstituted or even fully substituted by one or more substituents selected from the group consisting of C1-10 hydrocarbyl radicals that are unsubstituted or further substituted by one or more substituents selected from the group consisting of a halogen atom and a C1-4 alkyl radical; a halogen atom; a C1-8 alkoxy radical; a C6-10 aryl or aryloxy radical; an amide radical that is unsubstituted or substituted by up to two C1-8 alkyl radicals; a phosphide radical that is unsubstituted or substituted by up to two C1-8 alkyl radicals; silyl radicals of the formula --Si--(R)3, wherein each R is independently selected from the group consisting of hydrogen, a C1-8 alkyl or alkoxy radical, C6-10 aryl or aryloxy radicals; and germanyl radicals of the formula Ge-(R)3, wherein R is defined above.

[034] The cyclopentadienyl type ligand may be selected from the group consisting of a cyclopentadienyl radical, an indenyl radical and a fluorenyl radical, whose radicals are unsubstituted or even fully substituted by one or more substituents selected from the group consisting of a fluorine atom, a chlorine atom; C1-4 alkyl radicals; and a phenyl or benzyl radical that is unsubstituted or substituted by one or more fluorine atoms.

[035] The activatable Y ligands can be selected from the group consisting of a halogen atom, C1-4 alkyl radicals, C6-20 aryl radicals, C7-12 arylalkyl radicals, C6-10 phenoxy radicals, amide radicals which can be substituted by Petition 870240016554, dated 28 / 02 / 2024, p. 18 / 52 11 / 39 up to two C1-4 alkyl radicals and C1-4 alkoxy radicals. In some cases, Y is selected from the group consisting of a chlorine atom, a methyl radical, an ethyl radical, and a benzyl radical.

[036] Suitable phosphinimines are group 4 organometallic complexes containing a phosphinimine ligand (as described above) and a cyclopentadienyl (L) type ligand and two activatable ligands. The catalysts are not bridged. Activators

[037] Activators for the catalyst are typically selected from the group consisting of aluminoxanes and ionic activators. Alumoxanes (also known as “aluminoxanes”)

[038] A suitable alumoxane may have the formula: (R4)2AlO(R4AlO)mAl (R4)2, wherein each R4 is independently selected from the group consisting of C1-20 hydrocarbyl radicals in 0 to 50, preferably R4 is a C1-4 alkyl radical in 5 to 30. A non-limiting example of a suitable alumoxane is methylalumoxane (or “MAO”), wherein each R is methyl.

[039] Alumoxanes are well known as cocatalysts, particularly for metallocene-type catalysts. Alumoxanes are also readily available commercial items.

[040] The use of an alumoxane cocatalyst generally requires a molar ratio of aluminum to the transition metal in the catalyst of about 20:1 to about 1000:1; or, in other cases, from about 50:1 to about 250:1.

[041] Commercially available MAO typically contains free alkyl aluminum (e.g., trimethylaluminum or “TMA”) which can reduce catalyst activity and / or broaden the molecular weight distribution of the polymer. If a narrow molecular weight distribution polymer is required, it is preferable to treat such commercially available MAO with an additive that is capable of reacting with the Petition 870240016554, dated 28 / 02 / 2024, page 19 / 52 12 / 39 TMA; non-limiting examples of suitable additives include hindered alcohols or phenols. Cocatalysts “Ionic Activators”

[042] The so-called “ionic activators” are also well known for metallocene catalysts. See, for example, US Patent No. 5,198,401 (Hlatky and Turner) and US Patent No. 5,132,380 (Stevens and Neithamer).

[043] Although they do not wish to be bound to any theory, it is thought by those skilled in the art that “ionic activators” initially cause the abstraction of one or more of the activatable ligands in a way that ionizes the catalyst into a cation, then provides a bulky, labile, non-coordinating anion that stabilizes the catalyst in a cationic form. The bulky non-coordinating anion allows the polymerization of olefins to proceed in the center of the cationic catalyst (presumably because the non-coordinating anion is sufficiently labile to be displaced by the monomer that coordinates to the catalyst). Non-limiting examples of ionic activators are boron-containing ionic activators, such as: compounds of the formula [R5]+[B(R7)4]-, wherein B is a boron atom, R5 is an aromatic hydrocarbyl (e.g., triphenylmethyl cation) and each R7 is independently selected from the group consisting of phenyl radicals that are unsubstituted or substituted by 3 to 5 substituents selected from the group consisting of a fluorine atom, an alkyl or C1-4 alkoxy radical that is unsubstituted or substituted by a fluorine atom; and a silyl radical of the formula -Si-(R9)3; wherein each R9 is independently selected from the group consisting of a hydrogen atom and a C1-4 alkyl radical; and compounds of the formula [(R8)tZH]+[B(R7)4]-, where B is a boron atom, H is a hydrogen atom, Z is a nitrogen atom or a phosphorus atom, t is 2 or 3 and R8 is selected from the group consisting of C1-8 alkyl radicals, a phenyl radical that is unsubstituted or substituted by up to three C1-4 alkyl radicals or Petition 870240016554, dated 28 / 02 / 2024, p. 20 / 52 13 / 39 an R8 taken together with the nitrogen atom can form an aniline radical and R7 is defined above; and compounds of the formula B(R7)3, where R7 is defined above.

[044] In the above compounds, preferably, R7 is a pentafluorophenyl radical and R5 is a triphenylmethyl cation, Z is a nitrogen atom and R8 is a C1-4 alkyl radical or R8 taken together with the nitrogen atom forms an aniline radical which is substituted by two C1-4 alkyl radicals.

[045] The “ionic activator” can abstract one or more activatable ligands, so as to ionize the catalyst center into a cation, but not to covalently bind to the catalyst and to provide sufficient distance between the catalyst and the ionizing activator to allow a polymerizable olefin to enter the resulting active site.

[046] Examples of ionic activators include: triethylammonium tetra(phenyl)boron; tripropylammonium tetra(phenyl)boron; tri(n-butyl)ammonium tetra(phenyl)boron; trimethylammonium tetra(p-tolyl)boron; trimethylammonium tetra(o-tolyl)boron; tributylammonium tetra(pentafluorophenyl)boron; tripropylammonium tetra(o,p-dimethylphenyl)boron; tributylammonium tetra(m,m-dimethylphenyl)boron; tributylammonium tetra(p-trifluoromethylphenyl)boron; tributylammonium tetra(pentafluorophenyl)boron; tri(n-butyl)ammonium tetra(o-tolyl)boron; N,N-dimethylaniline tetra(phenyl)boron; N,N-diethylaniline tetra(phenyl)boron; N,N-diethylaniline tetra(phenyl)boron; N,N-2,4,6-pentamethylaniline tetra(phenyl)boron; di(isopropyl)ammonium tetra(pentafluorophenyl)boron; dicyclohexylammonium tetra(phenyl)boron; triphenylphosphonium tetra(phenyl)boron; tri(methylphenyl)phosphonium tetra(phenyl)boron; tri(dimethylphenyl)phosphonium tetra(phenyl)boron; tropylium tetraquipentafluorophenyl borate;triphenylmethyl tetrakispentafluorophenyl borate; benzene(diazonium) tetrakispentafluorophenyl borate; tropylium phenyltrispentafluorophenyl borate; triphenylmethyl phenyltrispentafluorophenyl borate; phenyltrispentafluorophenyl borate; Petition 870240016554, dated 28 / 02 / 2024, page 21 / 52 14 / 39 benzene(diazonium); tetrakis(2,3,5,6-tetrafluorophenyl)tropylium borate; tetrakis(2,3,5,6-tetrafluorophenyl)triphenylmethyl borate; tetrakis(3,4,5-trifluorophenyl)borate; tetrakis(3,4,5-trifluorophenyl)tropylium borate; tetrakis(3,4,5-trifluorophenyl)borate; tetrakis(1,2,2-trifluoroethenyl)tropylium borate; tetrakis(1,2,2-trifluoroethenyl)triphenylmethyl borate; tetrakis(1,2,2-trifluoroethenyl)benzene(diazonium) tetrakis(2,3,4,5-tetrafluorophenyl)tropylium borate; tetrakis(2,3,4,5-tetrafluorophenyl) triphenylmethyl borate; and tetrakisbenzene(diazonium) (2,3,4,5-tetrafluorophenyl)borate.

[047] Commercially available ionic activators include: tetrakispentafluorophenyl N,N-dimethylaniline borate; triphenylmethyl tetrakispentafluorophenyl borate; and trispentafluorophenylborane.

[048] The ionic activator can be used in about molar equivalents of boron to group IV metal in the catalyst. Suitable molar ratios of group IV metal catalyst to boron can range from about 1:1 to about 3:1, in other cases from about 1:1 to about 1:2.

[049] In some cases, the ionic activator may be used in combination with an alkylating activator (which may also serve as a scavenger). The ionic activator may be selected from the group consisting of (R3)pMgX2-p, wherein X is a halide and each R3 is independently selected from the group consisting of C1-10 alkyl radicals and p is 1 or 2; R3Li, wherein R3 is defined above; (R3)qZnX2-q wherein R3 is defined above, X is a halogen and q is 1 or 2; (R3)sAlX3-s, wherein R3 is defined above, X is a halogen and s is an integer from 1 to 3. Preferably, in the above compounds, R3 is a C1-4 alkyl radical and X is chlorine. Commercially available compounds include triethyl aluminum (TEAL), diethyl aluminum chloride (DEAC), dibutyl magnesium ((Bu)2Mg), and butylethyl magnesium (BuEtMg or BuMgEt). Petition 870240016554, dated 28 / 02 / 2024, page 22 / 52 15 / 39

[050] If the phosphinimine catalyst is activated with a combination of ionic activators (e.g., boron compounds) and alkylating agent, the molar ratio of group IV metal of the catalyst:metalloid (boron) of the ionic activator:metal of the alkylating agent can vary from about 1:1:1 to about 1:3:10, in other cases, from about 1:1.3:5 to about 1:1.5:3. Second Catalyst

[051] In one embodiment, a ZN catalyst is used in the second reactor. Any ZN catalyst system that works well for ethylene solution polymerization (optionally, with one or more alpha olefin comonomers, especially 1-butene; 1-hexene; or 1-octene) is potentially suitable. The ZN catalysts disclosed in U.S. Patents Nos. 10,023,706 and 9,695,309 are specific (but not limiting) examples. Polymerization Process

[052] The reactor temperature(s) in a high-temperature solution process is about 80 °C to about 300 °C, in other cases, about 120 °C to 250 °C. The upper temperature limit will be influenced by considerations that are well known to those skilled in the art, such as a desire to maximize the operating temperature (so as to reduce the viscosity of the solution) while still maintaining good polymer properties (as increased polymerization temperatures generally reduce the molecular weight of the polymer). In general, the upper polymerization temperature may be between about 200 and about 300 °C. A process using two reactors may be conducted at two temperatures with the temperature of the second reactor being higher than that of the first reactor. The most preferred reaction process is a “medium pressure process”, meaning that the pressure in the reactor(s) is preferably less than about 6,000 psi (about 42,000 kiloPascals or kPa).The pressures. Petition 870240016554, dated 28 / 02 / 2024, page 23 / 52 Preferred pressures are from about 10,000 to about 40,000 kPa (1,450 to 5,800 psi), more preferably from about 14,000 to about 22,000 kPa (2,000 psi to 3,000 psi).

[053] In some reaction schemes, the pressure in the reactor system must be high enough to maintain the polymerization solution as a single-phase solution and to provide the upstream pressure needed to feed the polymer solution from the reactor system through a heat exchanger system and into a devolatilization system. Other systems allow the solvent to separate into a polymer-rich and polymer-poor stream to facilitate polymer separation.

[054] The solution polymerization process can be carried out in a stirred “reactor system” comprising one or more stirred tank reactors or in one or more closed-circuit reactors or in a mixed-circuit and stirred tank reactor system. The reactors can be operated in tandem or parallel. In a double tandem reactor system, the first polymerization reactor preferably operates at a lower temperature. The residence time in each reactor will depend on the reactor design and capacity. In general, the reactors should be operated under conditions to obtain a complete mixing of the reagents. Furthermore, it is preferred that about 20 to about 60% by weight of the final polymer be polymerized in the first reactor, with the remainder polymerized in the second reactor.

[055] A useful solution polymerization process uses at least two polymerization reactors in series. The polymerization temperature in the first reactor is from about 80 °C to about 180 °C (in other cases, from about 120 °C to 160 °C) and the second reactor is normally operated at a higher temperature (up to about 220 °C). The most preferred reaction process is a “medium pressure process”, meaning that the pressure in each reactor is preferably less than about 6,000 psi (about 42,000 kilopascals or kPa), more Petition 870240016554, dated 28 / 02 / 2024, p. 24 / 52 17 / 39 preferably, from about 2,000 psi to about 3,000 psi (about 14,000 to about 22,000 kPa). EXAMPLES Testing Methods

[056] Mn, Mw and Mz (g / mol) were determined by high-temperature Gel Permeation Chromatography (GPC) with differential refractive index detection using universal calibration (ASTM-6467). The molecular weight distribution (MWD), also known to those skilled in the art as “polydispersibility” or “polydispersibility index,” is the ratio of the weighted average molecular weight (Mw) to the number average molecular weight (Mn).

[057] GPC in combination with Fourier Transform Infrared Spectroscopy (“GPC-FTIR”) was used to determine comonomer content as a function of molecular weight. After polymer separation by GPC, an online FTIR measures the concentration of the polymer and methyl terminal groups. Methyl terminal groups are used in branching frequency calculations. Conventional calibration allows the calculation of a molecular weight distribution.

[058] Mathematical deconvolutions were performed to estimate the relative amount of polymer, molecular weight, and comonomer content of the component made in each reactor.

[059] The short-chain branching frequency (SCB per 1000 carbon atoms) of copolymer samples was determined by Fourier Transform Infrared Spectroscopy (FTIR), according to ASTM D664501. A Thermo-Nicolet 750 Magna-IR spectrophotometer was used for the measurement. FTIR was also used to determine the internal, lateral, and terminal unsaturation levels (also called “unsats” for convenience). Petition 870240016554, dated 28 / 02 / 2024, page 25 / 52 18 / 39

[060] Comonomer content can also be measured using carbon-13 nuclear magnetic resonance (NMR) techniques, as discussed in Randall Rev. Macromol. Chemistry Phys., C29 (2&3), p. 285; US Patent No. 5,292,845 and WO 2005 / 121239.

[061] Information on the composition distribution was also obtained from temperature rise elution fractionation (TREF). A polymer sample (80 to 100 mg) was introduced into the reactor vessel of the Polymer Char crystal-TREF unit. The reactor vessel was filled with 35 mL of 1,2,4-trichlorobenzene (TCB), heated to the desired dissolution temperature (e.g., 150 °C) for 2 hours. The solution (1.5 mL) was then loaded onto the TREF column filled with stainless steel beads. After allowing equilibration at a given stabilization temperature (e.g., 110 °C) for 45 minutes, the polymer solution was allowed to crystallize with a temperature drop from the stabilization temperature to 30 °C (0.09 °C / minute). After equilibration at 30 °C for 30 minutes, the crystallized sample was eluted with TCB (0.75 mL / minute) with a temperature ramp of 30 °C until the stabilization temperature (0.25 °C / minute).The TREF column was cleaned at the end of the run for 30 minutes at the dissolution temperature. The data were processed using Polymer Char software, an Excel spreadsheet, and internally developed TREF software.

[062] CDBI is defined as the percentage of polymer whose composition is within 50% of the median comonomer composition. It is calculated from the composition distribution curve and the normalized cumulative integral of the composition distribution curve, as illustrated in U.S. Patent No. 5,376,439.

[063] The density of the polyethylene composition (g / cm3) was measured in accordance with ASTM D792.

[064] The melting indices I2, I6 and I21 for the polyethylene composition were measured, in accordance with ASTM D1238. For clarity: I2 is measured at 190 °C Petition 870240016554, dated 28 / 02 / 2024, page 26 / 52 19 / 39 with a load of 2.16 kilograms; I21 is measured at the same temperature with a load of 21.6 kg.

[065] The density and melt index of the first and second ethylene polymers comprising the polyethylene composition were determined based on composition models. The following equations were used to calculate the density and melt index I2 (US Reference Patent No. 8,022,143 B2, by Wang, assigned to NOVA Chemicals and published on September 20, 2011):$$ Density = 0.979863 - 5.95808 x 10⁻³ (-£L.) ' - 3.83133 x,' \1000c7 , 10-4[log10(Mj)]3- 5.77986 x 106(M''7u; í + 5.57395 x 103(Mz / Mw)°'25log10(Melting Index / 2) = 22.326528 + 3.467 x 10-3[log10(Mn)]3- 4.322582[log10(Mw)] - 1.80061 x 10-1[log10(Mz)]2+ 2.6478 x 10-2[log10(Mz)]3where Mn, Mw, Mz and SCB / 1000C are the deconvolution values ​​of the individual ethylene polymer components, as obtained from the deconvolution results described above.

[066] The primary melting peak (°C), heat of fusion (J / g), and crystallinity (%) were determined using differential scanning calorimetry (DSC) as follows: the instrument was first calibrated with indium; after a polymer sample was equilibrated at 0 °C; the temperature was increased to 200 °C at a heating rate of 10 °C / min; the melt was then held at this temperature for five minutes; the melt was then cooled to 0 °C at a cooling rate of 10 °C / min and held at 0 °C for five minutes; the specimen was heated a second time to 200 °C at a heating rate of 10 °C / min. Petition 870240016554, dated 28 / 02 / 2024, page 27 / 52 20 / 39 °C / min. The reported peak melting point (Tm), heat of fusion, and crystallinity are calculated based on the second heating. RHEOLOGY - FUSION RESISTANCE BY CAPILLARY RHEOMETRY

[067] The molten polymer is extruded through a capillary die under a constant extrusion rate. The extruded strand is pulled at increasing transport speed. The stretching force of the molten mass is continuously monitored and the maximum stable value of the force level at or before filament rupture is defined as the melt strength. The ratio between the extraction speed and the extrusion speed at the die exit is defined as the stretching ratio.

[068] The melt resistance is measured in a capillary rheometer (barrel diameter = 15 mm) with a 2 mm diameter flat die, L / D ratio 10:1 at 190 °C. Pressure transducer: 10,000 psi (68.95 MPa). Piston speed: 5.33 mm / min. Launch angle: 52°. Incremental transport speed: 50 to 80 m / min² or 65 ± 15 m / min². A molten polymer is extruded through a capillary die at a constant rate, and then the polymer bead is pulled at an increasing transport speed until it breaks. The maximum stable force value in the plateau region of a force versus time curve is defined as the melt resistance for the polymer. The melt stretching rate is defined as the ratio of the speed at the pulley to the speed at the die exit. Rheology - DMA

[069] The rheological properties were determined using frequency sweep test measurements on a rotational rheometer.

[070] A sample (in the form of a compression-molded disc) is placed in an environmental test chamber between two test geometries; the upper geometry attached to the drive shaft and the lower geometry attached to a base. The analysis is performed over a frequency range, at a deformation. Petition 870240016554, dated 28 / 02 / 2024, page 28 / 52 21 / 39 fixed and a constant temperature. The rheometer was a commercially available instrument (sold under the name DHR-3 by TA Instruments).

[071] This test technique offers an opportunity to study the various characteristics of a molten polymer where the elastic and viscous modulus (G' and G''), complex viscosity, complex modulus (G*), loss tangent, dynamic viscosity, out-of-phase component of the complex modulus, phase angle and other rheological properties as a function of oscillation frequency are generated to provide information on the rheological behavior in correlation to the molecular architecture.

[072] The rheological parameters derived from the test data are: crossover frequency, crossover modulus, three Ellis model constants: Ellis constant C1 (or zero shear viscosity), Ellis constant C2 (or reciprocal of the characteristic relaxation time), Ellis constant C3 (or power law exponent), Dow Rheology Index (DRI), Relaxation Spectrum Index (RSI), Melting Elasticity Index (G' @ G'' = 500 Pa), Viscosity Ratio, Cole-Cole and VGP plots.

[073] Relative elasticity, defined as the ratio of G' over G' at a frequency of 0.05 rad / s. Without limiting the invention to a theory, it has been observed that a relatively low relative elasticity correlates with powder densification during the rotational molding process.

[074] The Izod impact test was performed in accordance with ASTM D25610E1.

[075] The tensile impact test was performed in accordance with ASTM D1822-13.

[076] The rotomolded parts were prepared on a rotomolding machine sold under the trade name Rotospeed RS3-160 by Ferry Industries Inc. The machine has two arms that rotate around a central axis. Petition 870240016554, dated 28 / 02 / 2024, page 29 / 52 22 / 39 inside a closed oven. The arms are equipped with plates that rotate on an axis approximately perpendicular to the arm's axis of rotation. Each arm is fitted with six cast aluminum molds that produce plastic cubes with dimensions of 12.5 inches (31.8 cm) x 12.5 inches x 12.5 inches. The arm rotation was set to approximately 8 revolutions per minute (rpm) and the plate rotation was set to approximately 2 rpm. These molds produce parts with a nominal thickness of approximately 0.25 inches (0.64 cm) when initially filled with a standard charge of approximately 3.7 kg of polyethylene resin in powder form (35 US mesh size). The temperature inside the closed oven was maintained at 560 °F (293 °C). The molds and their contents were heated for a specified period of time until full densification of the powder was achieved. The molds were subsequently cooled in a controlled environment before the parts were removed.Samples were collected from the molded parts for density and color measurements. The ARM impact test was performed, in accordance with ASTM D5628, at a test temperature of -40 °C.

[077] The test samples to be impacted must be from a rotationally molded part. The test samples must be conditioned to achieve uniform cooling of the sample cross-section to not less than -40 °F ± 3.5 °F (-40 °C ± 2 °C).

[078] The impact testing technique for rotationally molded parts is commonly called the Bruceton Ladder Method or the Up-and-Down Method. The procedure establishes the height of a specific dart that will cause 50% of the specimens to fail. The percent ductility represents the percentage of failures that exhibited ductile characteristics. Samples are impact tested using a drop weight impact tester. If the sample did not fail at a given height / weight, the height or weight is incrementally increased until failure occurs. Once failure has occurred, the Petition 870240016554, dated 28 / 02 / 2024, p. 30 / 52 23 / 39 height / weight is decreased in the same increment and the process is repeated until all samples are used. The falling dart should impact the surface of the part that was in contact with the mold when it was molded. For polyethylene, a ductile failure is the desired failure mode that generally occurs in properly processed samples. A brittle failure or splintering failure generally indicates that the optimal properties were not obtained by the processing parameters used. Ductile: represented by the dart penetrating the sample, leaving a hole with fibrous fibers at the point of failure instead of cracking outward from the point of failure. The area under the dart elongated and thinned at the point of failure. Fragile: represented by the part physically breaking apart or cracking at the point of impact. The sample has little or no stretch. As used in this report, the term “ductility index” refers to the percentage of parts in a multi-part test that exhibit ductile failure. For example, if 10 parts are tested and 8 of them exhibit ductile failure (i.e., 80% of the parts exhibited ductile failure), then the test result is reported with a ductility index of 80%. The Resin

[079] Bimodal polyethylene compositions were prepared in a pilot-scale dual reactor plant. In this dual reactor process, the contents of the first reactor flow into the second reactor, both well mixed. The process operates using continuous feed streams. The catalyst (cyclopentadienyltri(butyl tertiary)phosphinimine dichloride) [note: this catalyst is referred to as “PI-cat” in the Tables describing experimental polymerizations] with activator was fed to the first reactor and a ZN catalyst to the second. The overall production rate was approximately 90 kg / h.

[080] The polymerization conditions are given in Table 1. Petition 870240016554, dated 28 / 02 / 2024, page 31 / 52 24 / 39

[081] The polymer compositions prepared at the pilot plant were stabilized using a conventional additive package for rotational molding applications before plate test experiments were performed. Rotomolding compositions typically contain an additive package to protect the polyethylene from degradation during the processing and to subsequently protect the rotomolded part from atmospheric exposure. The compositions in this disclosure are not intended to be limited to the use of any specific additive package.The inventive compositions shown in the examples contained the following additives (all quantities shown in parts per million by weight relative to the weight of the polyethylene): 500 ppm of hindered phenol (CAS Registry Number 2082-79-3); 550 ppm of phosphite (CAS Registry Number 31570-04-4); 450 ppm of diphosphite (CAS Registry Number 154862-43-8); 250 ppm of hydroxylamine (CAS Registry Number 143925-92-2); 750 ppm of Amine Light Stabilizer (HALS)-1 (CAS Registry Number 70624-18-9); 750 ppm of HALS-2 (CAS Registry Number 65447-77-0); and 750 ppm of Zinc Oxide.

[082] Table 2 discloses the GPC deconvolution results, in which Examples 1 and 2 were mathematically deconvolved into a first ethylene polymer (synthesized in reactor 1) and a second ethylene polymer (synthesized in reactor 2). The density and melt index of the first and second ethylene polymers were calculated based on fundamental kinetic models (with kinetic constants specific to each catalyst formulation), as well as feed and reactor conditions. The equations used to calculate densities and melt indices are described above (and in US Patent 8,022,143). The simulation was based on the dual reactor solution pilot plant configuration described above. The first ethylene interpolymer was fitted to a distribution based on a fundamental kinetic model that describes the behavior of the catalyst formulation. Petition 870240016554, dated 28 / 02 / 2024, page 32 / 52 25 / 39 single site. The second ethylene interpolymer was fitted to a distribution based on a fundamental kinetic model describing the behavior of the heterogeneous catalyst formulation. As shown in Table 2, in the case of Example 1, the 1st plus 2nd ethylene polymer comprise 88% by weight of Example 1; the remainder of Example 1 (12% by weight) was synthesized in the linkage reactor of tubes 1 and 2 (<3% by weight, having the same composition as the 1st ethylene polymer) and the tube following reactor 2 (<10% by weight, having the same composition as the 2nd ethylene polymer) before adding the catalyst deactivator.

[083] The properties of the pressed sheets of the rotomolded resins disclosed in this report (Examples 1 to 4) are shown in Table 3a; the comparative resins are shown in Table 3b (Comparative Examples 5 to 8). The properties of the rotomolded parts, as well as the pressed sheets made from the polyethylene compositions disclosed in this report, are shown in Table 4a; and comparatives in Tables 4b and 4c. Higher density resins generally do not perform well in rotomolded applications that also require good toughness. Examples 1 and 2 show superior performance compared to the comparative examples with a combination of high density, good toughness (ductility > 50%) and high mean failure energy under ideal molding conditions. Without wanting to be limited to theory, high density translates into greater stiffness and allows the use of less material to obtain comparable structural strength in a molded part. TABLE 1 Manufacturing Conditions Example 1 Example 2 Example 3 Example 4 Catalyst in R1 PI-cat PI-cat PI-cat PI-cat Catalyst in R2 ZN ZN ZN ZN Petition 870240016554, dated 28 / 02 / 2024, page 33 / 52 26 / 39 Ethylene divided between the first reactor (R1), second reactor (R2), and third reactor (R3) 0.29 / 71 26 / 74 0.30 / 0.70 / 0 Octene divided between the first reactor (R1), second reactor (R2), and third reactor (R3) 1 / 0 1 / 0 1 / 0 / 0 Octene to ethylene ratio in fresh feed 0.042 0.080 0.110 Hydrogen in reactor 1 (ppm) 2.7 2.4 2.7 Hydrogen in reactor 2 (ppm) 30.0 30.0 17.7 Reactor 1 temperature (°C) 139 139 140 Reactor 2 temperature (°C) 186 188 223 Conversion in reactor 1 (%) 92.1 92.0 91.7 Conversion in reactor 2 (%) 85.0 85.0 81.7 Catalyst feed in reactor 1 (ppm Ti) 0.14 0.22 0.39 0.59 SSC - Metal Al / Group 3 in reactor 1 (mol / mol) 100 100 65 65 SSC - Metal B / Group 4 in reactor 1 (mol / mol) 1.3 1.3 1.2 1.2 Catalyst feed in reactor 2 - PI (ppm Ti) Catalyst feed in reactor 2 - (ppm Ti) 2.4 2.9 6.2 8.5 Catalyst feed in reactor 2 - tert-chloride 2.0 2.0 1.9 1.9 Petition 870240016554, dated 28 / 02 / 2024, page 34 / 52 27 / 39 Butyl / Butyl(ethyl)magnesium (mol / mol) Catalyst feed to reactor 2 - Diethylaluminum ethoxide / Titanium tetrachloride (mol / mol) 1.4 1.4 1.3 1.3 Catalyst feed to reactor 2 Triethylaluminum / Titanium tetrachloride (mol / mol) 0.4 0.4 0.3 0.3 Catalyst feed to reactor 2 - Butyl(ethyl)magnesium / Titanium tetrachloride (mol / mol) 7.0 7.0 7.0 7.0 Polyethylene production rate (kg / h) 69.1 70.1 103.2 TABLE 1 - CONTINUED Manufacturing Conditions Comparative Example 8 Comparative Example 9 Comparative Example 10 Catalyst in R1 PI-cat PI-cat PI-cat Catalyst in R2 ZN PI-cat PI-cat Ethylene divided between the first reactor (R1), second reactor (R2) and third reactor (R3) 0.25 / 0.75 / 0 0.30 / 0.70 / 0 Petition 870240016554, dated 28 / 02 / 2024, page 35 / 52 28 / 39 Octene split between the first reactor (R1), the second reactor (R2), and the third reactor (R3) 1 / 0 / 0 1 / 0 / 0 Octene to ethylene ratio in fresh feed 0.135 0.144 Hydrogen in reactor 1 (ppm) 1.2 0.9 Hydrogen in reactor 2 (ppm) 24.3 2.9 Reactor 1 temperature (°C) 138 138 Reactor 2 temperature (°C) 212 210 Conversion in reactor 1 (%) 91.5 89.6 Conversion in reactor 2 (%) 91.9 88.0 Catalyst feed in reactor 1 (ppm Ti) 0.21 0.14 SSC - Metal Al / Group 3 in reactor 1 (mol / mol) SSC - Metal B / Group 4 in reactor 1 (mol / mol) Catalyst feed in Reactor 2 PI (ppm of Ti) 0.69 Catalyst feed to reactor 2 (ppm of Ti) 4.7 Catalyst feed to reactor 2 tert-Butyl chloride / Butyl(ethyl)magnesium (mol / mol) 2.0 Catalyst feed to reactor 2 Diethylaluminum ethoxide / titanium tetrachloride (mol / mol) 1.4 Petition 870240016554, dated 28 / 02 / 2024, page 36 / 52 29 / 39 Catalyst feed to reactor 2: Triethylaluminum / titanium tetrachloride (mol / mol) 0.4; Catalyst feed to reactor 2: Butyl(ethyl)magnesium / titanium tetrachloride (mol / mol) 7.0; Polyethylene production rate (kg / h) 94.1 TABLE 2 Deconvolution results to describe the overall molecular weight distribution Example 1 Example 2 12 ETHYLENE POLYMER (R1 - Deconvolution Studies) Catalyst System PI-cat PI-cat Weight Fraction (%) 29% 26% Mn 53.915 50.107 Mw 107.831 100.214 Mz 161.747 150.321 Polydispersity Index (Mw / Mn) 2.0 2.0 Freq. Branching / 1000C (SCB1) 1.4 3.6 Density Estimate (g / cm3) (d1) Equation (1) 0.9370 0.9316 Melting Index Estimate h (g / 10 min) Equation (2) 0.63 0.83 22 ETHYLENE POLYMER (R2 - Deconvolution Studies) Catalyst System ZN ZN Weight Fraction (%) 71% 74% Mn 19.974 19.875 Petition 870240016554, dated 28 / 02 / 2024, page 37 / 52 30 / 39 Mw 49.054 49.062 Mz 94.329 94.638 Polydispersity Index (Mw / Mn) 2.5 2.5 Branching Frequency / 1000C (SCB2) 0.4 1.0 Density Estimate (g / cm3) (d2) Equation (1) 0.9514 0.9491 Melting Index Estimate I2 (g / 10 min) Equation (2) 13.49 13.48 GENERAL ETHYLENE POLYMER (Deconvolution Studies) Mn 23.453 22.709 Mw 63.840 60.416 Mz 119.603 112.405 Polydispersity Index (Mw / Mn) 2.7 2.7 TABLE 3a Resin Characteristics Example 1 Example 2 Example 3 Example 4 Density (g / cm3) 0.9506 0.9452 0.9412 0.9422 Melting Index I2 (g / 10 min) 6.4 6.4 6.7 7.75 Melting Index I21 (g / 10 min) 129 133 136 184 Stress Exponent 1.19 1.20 1.18 1.23 Melting Flow Rate (I21 / I2) 20.3 20.9 20.1 23.8 CTREF / CTREF SLOW High Peak Elution (°C) 95.1 94.9 Low Peak Elution (°C) 85.9 86.0 CDBI50 62.8 68.8 Branching Frequency - FTIR Petition 870240016554, dated 28 / 02 / 2024, pages 38 / 52 31 / 39 Frequency of Branching / 100°C 1.9 3.5 4.2 4.4 Comonomer ID octene octene octene octene Comonomer content (% by mol) 0.4 0.7 0.8 0.9 Comonomer content (% by weight) 1.5 2.7 3.3 3.4 Internal Unsaturation / 10°C 0 0.001 0.002 0.003 Side Chain Unsaturation / 10°C 0 0 0.001 0.001 Terminal Unsaturation / 10°C 0.043 0.043 0.054 0.056 GPC - Conventional Mn 20.349 22.923 22.572 23.948 Mw 67.425 94,999 62,322 62,255 Mz 136,23 9 247,612 117,398 125,666 Polydispersity Index (Mw / Mn) 3.31 4.14 2.8 2.6 Index (Mz / Mw) 2.0 2.6 1.9 2.0 GPC-FTIR Branching Frequency Comonomer Distribution Reverse 0 Reverse Reverse Reverse Rheology Shear Viscosity Zero -190 °C (Pa-s) 1396 1401 1266 1152 Relative Elasticity G7G” at 0.05 rad / s - 190 °C 0.022 0.017 0.013 0.014 Average Melting Strength -190 °C (cN) 1.02 0.94 0.68 0.66 Average Stretch Rate - 190 °C (%) 1388.8 1502.5 1440.7 1581.7 Petition 870240016554, dated 28 / 02 / 2024, pp. 39 / 52 32 / 39 TABLE 3b Resin Characteristics Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Density (g / cm3) 0.9477 0.9436 0.9408 0.9381 Melting Index I2 (g / 10 min) 6.94 5.99 6.63 4.56 Melting Index I21 (g / 10 min) 205 154 156 108 Stress Exponent 1.31 1.27 1.24 1.24 Melting Flow Rate (I21 / I2) 29.5 25.6 23.5 23.7 CTREF / CTREF SLOW High Peak Elution (°C) 97.5 97.6 95.6 Low Peak Elution (°C) 83.3 CDBI50 terpolymer 42.2 52.3 Branching Frequency - FTIR Branching Frequency / 1000°C C4 (1-butene) and C8 (1-octene) 5.9 5.4 5.1 Comonomer ID C4 and C8 Hexene hexene octene Comonomer content (% by mol) C4 and C8 1.2 1.1 1.0 Petition 870240016554, dated 28 / 02 / 2024, pages 40 / 52 33 / 39 Comonomer content (% by weight) C4 and C8 3.4 3.2 3.8 Internal Unsaturation / 100°C 0.001 0 0.001 0.003 Side Chain Unsaturation / 100°C 0 0.004 0.001 0.000 Terminal Unsaturation / 100°C 0.011 0.011 0.015 0.054 GPC - Conventional Mn 22.081 15.603 25.692 24.649 Mw 72.138 69.049 69.741 66.330 Mz 177.243 171.744 166.490 131.250 Polydispersity Index (Mw / Mn) 3.3 4.43 2.7 2.7 Index (Mz / Mw) 2.5 2.5 2.4 2.0 GPC-FTIR Branching Frequency Reverse Normal Normal Reverse Comonomer Distribution Rheology Zero Shear Viscosity 190 °C (Pa-s) 1639 1383 2013 Relative Elasticity G7G” at 0.05 rad / s -190 °C 0.046 0.020 0.019 Average Melting Strength - 190 °C (cN) 0.79 Petition 870240016554, dated 28 / 02 / 2024, pages 41 / 52 34 / 39 Average Stretch Rate 190 °C (%) 1813.4 TABLE 3c Resin Characteristics Comparative Example 9 Comparative Example 10 Density (g / cm3) 0.9365 0.937 Melting Index I2 (g / 10 min) 5.03 5.06 Melting Index I21 (g / 10 min) 160 249 Stress Exponent 1.34 1.48 Melting Flow Rate (I21 / I2) 31.8 49.2 CTREF / CTREF SLOW High Peak Elution (°C) 89.1 89.2 Low Peak Elution (°C) 85.3 84.3 CDBI50 82 86.5 Branching Frequency - FTIR Freq. Branching / 100°C 6.2 6.7 Comonomer ID octene octene Comonomer Content (% by mol) 1.2 1.3 Comonomer Content (% by weight) 4.8 5.2 Internal Unsaturation / 100°C 0.027 0.018 Side Chain Unsaturation / 100°C 0.005 0.004 Terminal Unsaturation / 100°C 0.017 0.013 GPC - Conventional Mn 27.251 23.655 Mw 68.845 71.156 Petition 870240016554, dated 28 / 02 / 2024, pages 42 / 52 35 / 39 Mz 154,100 212,486 Polydispersity Index (Mw / Mn) 2.5 3.0 Index (Mz / Mw) 2.2 3.0 Branching Frequency GPC-FTIR Reverse Comonomer Distribution Reverse Rheology Shear Viscosity Zero -190 °C (Pa-s) 2069 2322 Relative Elasticity G7G” at 0.05 rad / s - 190 °C 0.023 0.032 Average Melting Strength -190 °C (cN) Average Stretch Rate - 190 °C (%) TABLE 4a Results of Tests Performed on Compression Molded Plates and Rotomolded Samples Example 1 Example 2 Example 3 Example 4 Tensile and Flexural Properties (Plates) Tensile Strength (MPa) 27.5 23.9 21.5 21.8 Ultimate Tensile Strength - Stress at rupture (MPa) 30.5 30.5 29.3 16.2 Secant Modulus of Tension 1% (MPa) 1279.6 1074 856 886 Secant Modulus of Flexion 1% (MPa) 1136 946 840 841 Impact Properties (Plates) Izod Impact (ft-lb / in) 1.5 1.1 2.5 1.6 Petition 870240016554, dated 28 / 02 / 2024, pp. 43 / 52 36 / 39 Tensile impact (ft-lb / in2) 91.8 112.7 134.7 120.6 Environmental stress crack resistance ESCR Cond. B at 10% CO630 (h) 21 21 5-22 5 - 16 ESCR Cond. B at 100% CO630 (h) 17 25 51 55 Rotomolding Performance (1 / 4” molded part thickness) Ideal times (min) at oven temperature of 560 °F 18-20 18-20 18-20 18-20 Average Failure Energy (ft.lb) under ideal conditions 180-189 188-181 155-193 180-193 Ductility (%) under ideal conditions 100-100 100-100 100-91 100-91 As well as density (g / cm3) under ideal conditions 0.9540-0.9439 0.9475-0.9476 0.9428-0.9425 0.9430-0.9423 Petition 870240016554, dated 28 / 02 / 2024, pp. 44 / 52 37 / 39 TABLE 4b Results of Tests Performed on Compression Molded Plates and Rotomolded Samples Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Tensile and Flexural Properties (Plates) Tensile Strength (MPa) 22.5 22.7 21.7 20.7 Ultimate Tensile Strength - Stress at Rupture (MPa) 16.5 15.9 14.1 29.3 Tensile Drying Modulus 1% (MPa) 961 1017.9 909.8 864 Flexural Secant Modulus 1% (MPa) 933 952 897 814 Impact Properties (Plates) Izod Impact (ft-lb / in) 1.5 1.4 Tensile Impact (ft-lb / in2) 92.0 79.1 Resistance to Environmental Stress Cracking ESCRCond. Ba 10% CO630 (h) 42 189 7-22 92 ESCR Cond. B at 100% CO630 (h) 15 81 30 > 1000 Rotomolding Performance (1 / 4” molded part thickness) Ideal times (min) at oven temperature of 560 °F 18-20 20-22 18-20 20-22 Average failure energy (ft.lb) at 164 - 184 58 - 110 57 - 84 172 - 183 Petition 870240016554, dated 28 / 02 / 2024, pages 45 / 52 38 / 39 Ideal conditions Ductility (%) under ideal conditions 63-75 0-7 0-0 100 - 100 As well as density (g / cm3) under ideal conditions 0.9514 - 0.9512 0.9445 - 0.9442 0.9401 - 0.9397 0.9422 - 0.9422 TABLE 4c Test results performed on compression-molded plates and Rotomolded Samples Comparative Example 9 Comparative Example 10 Tensile and Flexural Properties (Plates) Tensile Strength (MPa) 21.6 19.6 Ultimate Tensile Strength - Tensile Strength at Rupture (MPa) 14.3 15.3 Secant Modulus of Tension 1% (MPa) 875 780 Secant Modulus of Flexion 1% (MPa) 784 694 Impact Properties (Plates) Izod Impact (ft-lb / in) Tensile Impact (ft-lb / in2) Resistance to Cracking by Environmental Stress ESCR Cond. B at 10% CO630 (h) 79 144 ESCR Cond. B at 100% CO630 (h) >1008 >1006 Rotomolding Performance (1 / 4” molded part thickness) Ideal times (min) at oven temperature of 560 °F 18 - 20 18 - 20 Petition 870240016554, dated 28 / 02 / 2024, pp. 46 / 52 39 / 39 Average Fault Energy (ft.lb) under ideal conditions 171 -187 164-173 Ductility (%) under ideal conditions 100-100 60 - 27 As well as density (g / cm3) under ideal conditions 0.9392 - 0.9391 0.9397 - 0.9397 INDUSTRIAL APPLICATION

[084] High-density polyethylene compositions are provided that offer high rigidity and ductility and that can be useful in the preparation of rotomolded articles. Petition 870240016554, dated 28 / 02 / 2024, pp. 47 / 52

Claims

1 / 4 CLAIMS 1. Bimodal polyethylene composition CHARACTERIZED in that it has 1) a molecular weight distribution, Mw / Mn, of 2.3 to 5.5, wherein Mw and Mn are determined as measured by ASTM-6467; 2) a density of 0.940 to 0.957 g / cm3, determined in accordance with ASTM D792; 3) a melting index, I2, as measured by ASTM D1238 at 190 °C using a 2.16 kg charge of 4 to 10 grams for 10 minutes; and 4) a relative elasticity, G' / G'' when measured at 190 °C and 0.05 rad / second less than 0.03 rad / s, wherein said bimodal polyethylene composition comprises: A. 10 to 70% by weight of a first ethylene copolymer having: Ai a melting index, I2, of 0.4 to 5 grams per 10 minutes, calculated according to the method described in the descriptive report; A.ii. a molecular weight distribution, Mw / Mn, of 1.8 to 3.0; and A.iii. a density of 0.920 to 0.950 g / cm3; B. 90 to 30% by weight of a second ethylene copolymer having: Bi a melting index, I2, of 4 to 1500 grams per 10 minutes, calculated according to the method described in the descriptive report; B.ii. a molecular weight distribution, Mw / Mn, of 2.3 to 6.0; and B.iii.a density that is greater than the density of said first ethylene copolymer, but less than 0.967 g / cm3; provided that the density of said first ethylene copolymer is less than the density of said second ethylene copolymer by a value of 0.010 to 0.035 g / cm3. Petition 870240016554, dated 28 / 02 / 2024, p. 48 / 52 2 / 4 2. Polyethylene composition, according to claim 1, CHARACTERIZED in that said first ethylene copolymer is further defined as having: A.iv. a number average molecular weight, Mn, of 35,000 to 80,000; A.vi. a weighted average molecular weight, Mw, of 70,000 to 150,000; A.vi. a Mz of 120,000 to 250,000; and A.vii.a number of short-chain branches (SCB1) per thousand carbon atoms from 1 to 5; wherein the Mw / Mn of said first ethylene copolymer is from 2 to 3; and the melting index, I2, of said first ethylene copolymer is from 0.5 to 4.0 grams per 10 minutes, calculated according to the method described in the descriptive report.

3. Polyethylene composition, according to claim 1 or 2, CHARACTERIZED in that said second ethylene copolymer is further defined by having: B.iv. a number average molecular weight, Mn, from 12,000 to 30,000; B.v. a weighted average molecular weight, Mw, from 28,000 to 72,000; B.vi. an Mz from 70,000 to 150,000; B.vii. a number of short-chain branches (SCB2) per thousand carbon atoms from 0.1 to 2; and B.viii.a density greater than the density of said first ethylene copolymer, but less than 0.965 g / cm3; wherein the Mw / Mn of said second ethylene copolymer is from 2.3 to 5.0; and the melting index, I2, of said second ethylene copolymer is from 4 to 100 grams per 10 minutes, calculated according to the method described in the descriptive report; on the condition that the density of said first ethylene copolymer is less than the density of said second ethylene copolymer by a value of 0.010 to 0.030 g / cm3. Petition 870240016554, dated 28 / 02 / 2024, p. 49 / 52 3 / 4 4. Polyethylene composition according to claim 1, CHARACTERIZED in that said bimodal polyethylene composition has a comonomer content of less than 1.2 mol%, as determined by the FTIR method. 5.Polyethylene composition according to claim 1, characterized in that said first and second ethylene copolymers are ethylene-1-octene copolymers.

6. Polyethylene composition according to claim 1, characterized in that said bimodal polyethylene composition is prepared by contacting ethylene and an alpha-olefin with a polymerization catalyst under solution polymerization conditions in at least two polymerization reactors.

7. Rotomolded part characterized in that it is prepared with a polyethylene composition as defined in any one of claims 1 to 3.

8. Rotomolded part according to claim 7, characterized in that it has a ductility index of 80 to 100%.

9. Rotomolded part, according to claim 8, CHARACTERIZED in that it has an average failure energy greater than 162.7 J (120 ft.lb) in samples 0.64 cm (0.250 inch) thick tested according to ASTM D5628 at a test temperature of -40 °C.

10. Rotomolded part, according to claim 7 or 8, CHARACTERIZED in that said first ethylene copolymer is prepared with a single-site catalyst and said second ethylene copolymer is prepared with a Ziegler Natta catalyst.

11. Process for the production of hollow polyolefin articles, CHARACTERIZED in that it comprises charging the composition of Petition 870240016554, dated 28 / 02 / 2024, p. 50 / 52 4 / 4 bimodal polyethylene, as defined in claim 1, in a mold, heat that mold in an oven above 280 °C, so that the stabilized polyolefin melts, rotate the mold around at least 2 axes, the plastic material spreading to the walls, cool the mold while still rotating, open it and remove the resulting hollow article. Petition 870240016554, dated 28 / 02 / 2024, p. 51 / 52.

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