Methods for activating chromium catalyst to reduce gel syndrome and improve melting index potential

Description

1 / 73 METHODS FOR ACTIVATING CHROMIUM CATALYST TO REDUCE GEL SYNDROME AND IMPROVE MELTING INDEX POTENTIAL REFERENCE TO RELATED REQUEST

[0001] This application is being filed on April 30, 2024, as a PCT International Patent Application and claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 499,507, filed on May 2, 2023, the disclosure of which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION

[0002] This disclosure generally relates to methods for activating supported chromium precatalysts and to the use of activated chromium catalysts for polymerizing olefins. FUNDAMENTALS OF THE INVENTION

[0003] Supported chromium precatalysts are activated by exposure to an oxygen-containing atmosphere (e.g., air) at elevated temperatures to convert at least a portion of lower-valence chromium to an oxidation state of +6 (hexavalent chromium). However, in commercial practice, activation of large quantities of supported chromium catalysts often results in relatively low conversion to Cr(VI), and the resulting activated chromium catalyst often cannot efficiently produce relatively high melt index polymers with low film gel content. It would be beneficial to overcome these shortcomings with alternative catalyst activation methods, and consequently, it is to these purposes that the present invention is generally directed. SUMMARY OF THE INVENTION

[0004] This summary is provided to present a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify necessary or essential features of the claimed subject matter. This summary also does not Petition 870250088394, dated 09 / 30 / 2025, page 89 / 171 2 / 73 should be used to limit the scope of the claimed subject matter.

[0005] Aspects of this invention are directed to processes for producing an activated (or calcined) chromium catalyst, and such processes may comprise (i) placing a precatalyst in contact with a first inert atmosphere at a temperature T1 in a range of 500 °F to 700 °F (260 °C to 371 °C), wherein the precatalyst comprises a silica support and 0.1 to 5% by weight of chromium, 0.1 to 10% by weight of titanium and 1 to 5 mol of nitrogen / mol of titanium, (ii) subjecting the precatalyst to cycles of a first oxidizing atmosphere at a temperature T2 in a range of 500 °F to 700 °F (260 °C to 371 °C) and a second inert atmosphere at a temperature T3 in a range of 700 °F to 900 °F (371 °C to 482 °C). °C), in which the first oxidizing atmosphere causes an exothermic increase in temperature from T2 to T3, thus triggering the introduction of the second inert atmosphere which results in cooling to T2,until the exothermic temperature increase in the first oxidizing atmosphere is less than or equal to 50 °F (28 °C) within 15 min or when heat must be added to maintain T3 in the presence of the first oxidizing atmosphere, (iii) heat the precatalyst in a third inert atmosphere to a temperature T4 in a range of 1000 °F to 1400 °F (538 °C to 760 °C) and maintain the precatalyst at T4 in the third inert atmosphere for a retention time t1 in a range of 1 h to 15 h, (iv) cool the precatalyst in a fourth inert atmosphere to a temperature T5 in a range of 900 °F to 1200 °F (482 °C to 649 °C), wherein T5 is less than T4, (v) subject the precatalyst to a second oxidizing atmosphere at T5 for a retention time t2 in a range of 30 min to 10 h, (vi) cool in a third oxidizing atmosphere to a temperature T6 in a range of 500 °F to 700 °F (260 °C to 371 °C) to produce the activated (calcined) chromium catalyst,and (vii) purge the activated (calcined) chromium catalyst in a fifth inert atmosphere at T6 and cool to room temperature.,

[0006] Polymerization processes for olefins are also provided in this document. These polymerization processes can Petition 870250088394, dated 09 / 30 / 2025, page 90 / 171 3 / 73 comprise (I) carrying out any process to produce the activated chromium catalyst disclosed in this document and (II) bringing the activated chromium catalyst and an optional cocatalyst into contact with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

[0007] Other aspects of this invention are directed to ethylene polymers (which are typically in the form of pellets or granules) that are characterized by a high-charge melt index (HLMI) in the range of 10 to 80 g / 10 min and a density in the range of 0.93 to 0.96 g / cm3 (or a melt index (MI) in the range of 0.1 to 1 g / 10 min and a density in the range of 0.93 to 0.96 g / cm3). These ethylene polymers may have a total film gel count (or a catalyst particle gel count) of less than or equal to 100 gels per ft² of 25 micron thick film, wherein the film gels span a size greater than 200 µm (and cause catalyst particles to count towards the catalyst particle gel count) and may contain 150 to 680 ppm of silica, 1.5 to 6.8 ppm of chromium, and 1.5 to 40 ppm of titanium.

[0008] Both the aforementioned summary and the detailed description below provide examples and are explanatory only. Consequently, the preceding summary and the detailed description below should not be considered restrictive. Furthermore, features or variations may be provided beyond those set forth in this document. For example, certain aspects may be directed to various combinations and subcombinations of features described in the detailed description. BRIEF DESCRIPTION OF THE FIGURES

[0009] The following figures are part of this descriptive report and are included to further demonstrate certain aspects of the present invention. The invention can be better understood by reference to one or more of these figures in combination with the detailed description of specific embodiments presented in this document. Petition 870250088394, dated 09 / 30 / 2025, page 91 / 171 4 / 73

[0010] FIG. 1 presents a temperature versus time graph for a representative activation method similar to that of the FG Activation Methods.

[0011] FIG. 2 presents a temperature versus time graph for the exothermic elimination portion of FIG. 1.

[0012] FIG. 3 shows a temperature versus time graph for a representative activation method similar to that of the H Activation Method.

[0013] Although the inventions disclosed in this document are susceptible to various modifications and alternative forms, only a few specific embodiments have been shown by way of example in the figures and are described in detail below. The figures and detailed descriptions of these specific embodiments are not intended to limit the breadth and scope of creative concepts or the appended claims in any way. Rather, the figures and detailed written descriptions are provided to illustrate the inventive concepts to one skilled in the art and to enable such a person to make and use the inventive concepts. DEFINITIONS

[0014] To define more clearly the terms used in this document, the following definitions are provided. Unless otherwise indicated, the following definitions apply to this disclosure. If a term is used in this disclosure but is not specifically defined in this document, the definition from the IUPAC Compendium of Chemical Terminology, 2nd Ed. (1997) may be applied, provided that such definition does not conflict with any other disclosure or definition applied in this document, or render undefined or ineffective any claim to which such definition applies. To the extent that any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided in this document, the definition or usage provided in this document shall prevail. Petition 870250088394, dated 09 / 30 / 2025, page 92 / 171 5 / 73

[0015] In this document, subject matter features are described in such a way that, within the particular aspects, a combination of different features can be anticipated. For each and every aspect and each and every feature disclosed in this document, all combinations that do not negatively affect the catalysts, compositions, processes, or methods described in this document are contemplated, with or without explicit description of the particular combination. Furthermore, unless explicitly stated otherwise, any aspect or feature disclosed in this document may be combined to describe inventive catalysts, compositions, processes, or methods consistent with this disclosure.

[0016] Generally, groups of elements are indicated using the numbering scheme indicated in the version of the periodic table of elements published in Chemical and Engineering News, 63(5), 27, 1985. In some cases, a group of elements may be indicated using a common name assigned to the group; for example, alkali metals for Group 1 elements, alkaline earth metals for Group 2 elements, transition metals for Group 3-12 elements, and halogens or halides for Group 17 elements.

[0017] The term hydrocarbon, whenever used in this descriptive report and in the claims, refers to a compound containing only carbon and hydrogen, whether saturated or unsaturated. Other identifiers may be used to indicate the presence of particular groups in the hydrocarbon (for example, halogenated hydrocarbon indicates the presence of one or more halogen atoms replacing an equivalent number of hydrogen atoms in the hydrocarbon). Non-limiting examples of hydrocarbons include alkanes (linear, branched and cyclic), alkenes (olefins) and aromatics, among other compounds.

[0018] For any particular compound or group disclosed in this document, any name or structure (general or specific) presented is intended to encompass all isomers, regioisomers, conformational stereoisomers and mixtures thereof that may arise from a set in Petition 870250088394, dated 09 / 30 / 2025, page 93 / 171 6 / 73 particular substituents, unless otherwise specified. The name or structure (general or specific) also covers all enantiomers, diastereomers and other optical isomers (if any), whether in enantiomeric or racemic forms, as well as mixtures of stereoisomers, as would be recognized by one skilled in the art, unless otherwise specified. For example, a general reference to pentane includes n-pentane, 2-methylbutane and 2,2-dimethylpropane; and a general reference to a butyl group includes an n-butyl group, a sec-butyl group, an isobutyl group and a t-butyl group.

[0019] The terms "contact" and "submit" and similar terms are used in this document to describe catalysts, compositions, processes and methods in which materials or components are combined in any order, in any manner and for any period of time, unless otherwise specified. For example, materials or components may be blended, mixed, suspended, dissolved, reacted, treated, impregnated, compounded, fluidized or otherwise combined in any other way or by any suitable method or technique.

[0020] BET surface area, as used in this document, means the surface area as determined by the Brunauer, Emmett and Teller (BET) nitrogen adsorption method according to ASTM D1993-91, and as described, for example, in Brunauer, S., Emmett, PH, and Teller, E., Adsorption of gases in multimolecular layers, J. Am. Chem. Soc., 60, 3, pp. 309-319.

[0021] The term polymer is used in this document generically to include homopolymers, copolymers, olefin terpolymers and the like, as well as alloys and blends thereof. The term polymer also includes impact, interlocking, grafting, random and alternating copolymers. A copolymer is derived from an olefin monomer and an olefin comonomer, while a terpolymer is derived from an olefin monomer and two olefin comonomers. Consequently, polymer encompasses copolymers and terpolymers derived from any olefin monomers and comonomers. Petition 870250088394, dated 09 / 30 / 2025, page 94 / 171 7 / 73 disclosed in this document. Similarly, the scope of the term polymerization includes homopolymerization, copolymerization, and terpolymerization. Therefore, an ethylene polymer includes ethylene homopolymers, ethylene copolymers (e.g., ethylene / α-olefin copolymers), ethylene terpolymers and the like, as well as blends or mixtures thereof. Thus, an ethylene polymer encompasses polymers frequently referred to in the art as LLDPE (linear low-density polyethylene) and HDPE (high-density polyethylene). As an example, an olefin copolymer, such as an ethylene copolymer, may be derived from ethylene and a comonomer, such as 1-butene, 1-hexene, or 1-octene. If the monomer and comonomer are ethylene and 1-hexene, respectively, the resulting polymer may be categorized as an ethylene / 1-hexene copolymer.The term polymer also includes all possible geometric configurations, unless otherwise defined, and such configurations may include isotactic, syndiotactic, and random symmetries. Furthermore, unless otherwise defined, the term polymer is also intended to include all polymers of molecular weight.

[0022] In this disclosure, although catalysts, compositions, processes and methods are described in terms of comprising several components or steps, catalysts, compositions, processes and methods may also consist essentially of or consist of the various components or steps, unless otherwise defined. The terms a, an and the are intended to include plural alternatives, for example, at least one, unless otherwise specified.

[0023] Various types of ranges are disclosed in the present invention. When a range of any type is disclosed or claimed, the intention is to disclose or claim individually every possible number that such range could reasonably encompass, including the endpoints of the ranges, as well as any sub-ranges and combinations of sub-ranges covered therein. For example, the oxidizing atmosphere may contain a range of oxygen contents in aspects of this invention. By a disclosure that the atmosphere Petition 870250088394, dated 09 / 30 / 2025, p. 95 / 171 8 / 73 The oxidant may contain from 1 to 100% oxygen by volume; the intention is to demonstrate that the oxygen content can be any amount within the range and, for example, may include any range or combination of ranges from 1 to 100% by volume, such as 1 to 50% by volume, 2 to 30% by volume, 3 to 25% by volume, or 4 to 21% by volume of oxygen, and so on. Similarly, all other ranges disclosed in this document should be interpreted in a manner similar to this example.

[0024] In general, a quantity, size, formulation, parameter, range, or other quantity or characteristic is about or approximate, whether or not expressly stated as such. Whether or not modified by the term about or approximate, claims include equivalents to quantities or characteristics.

[0025] Although any methods, devices and materials similar or equivalent to those described in this document may be used in the practice or testing of the invention, the typical methods, devices and materials are described in this document.

[0026] All publications and patents mentioned in this document are incorporated herein by reference in their entirety for the purpose of describing and disclosing, for example, the constructs and methodologies that are described in the publications and patents, which may be used in connection with the present invention described. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention is generally directed to the conversion of lower valence-supported chromium precatalysts into activated (hexavalent) chromium catalysts, which are subsequently used in olefin polymerization processes.

[0028] One objective of the invention is to produce activated chromium catalysts with a high Cr(VI) content and catalytic activity. Another objective is to produce activated chromium catalysts with a high melt index potential, so that ethylene-based polymers can be produced with molecular weights Petition 870250088394, dated 09 / 30 / 2025, page 96 / 171 9 / 73 lower and / or higher melt flow rates. Another goal is to produce activated catalysts with high melt index potential at relatively low calcination / activation temperatures. Another goal is to produce activated chromium catalysts that can produce ethylene-based polymers with a wide molecular weight distribution and low levels of long-chain branching. Another goal is to produce activated chromium catalysts that can produce ethylene-based polymers with surprisingly low film gel levels. Another goal is to produce activated chromium catalysts that can produce ethylene-based polymers that have improved extrusion processability for a multitude of applications, including blown film, tubing, and blow-molded products. These and other benefits are described below. PROCESSES FOR ACTIVATING CHROMIUM CATALYSTS

[0029] This document discloses a process for producing an activated (or calcined) chromium catalyst. This process may comprise (i) placing a precatalyst in contact with a first inert atmosphere at a temperature T1 in a range of 500 °F to 700 °F (260 °C to 371 °C), wherein the precatalyst comprises a silica support and 0.1 to 5% by weight of chromium, 0.1 to 10% by weight of titanium and 1 to 5 mol of nitrogen / mol of titanium, (ii) subjecting the precatalyst to cycles of a first oxidizing atmosphere at a temperature T2 in a range of 500 °F to 700 °F (260 °C to 371 °C) and then a second inert atmosphere at a temperature T3 in a range of 700 °F to 900 °F (371 °C to 482 °C), wherein the first oxidizing atmosphere causes an exothermic temperature increase from T2 to T3, triggering thus the introduction of the second inert atmosphere which results in cooling down to T2,until the exothermic temperature rise in the first oxidizing atmosphere is less than or equal to 50 °F (28 °C) within 15 min or when heat must be added to maintain T3 in the presence of the first oxidizing atmosphere, (iii) heat the precatalyst in a third inert atmosphere to a temperature T4 in a range of 1000 °F to 1400 °F, Petition 870250088394, dated 09 / 30 / 2025, page 97 / 171 10 / 73 (538 °C to 760 °C) and hold the precatalyst at T4 in a third inert atmosphere for a retention time t1 in a range of 1 h to 15 h, (iv) cool the precatalyst in a fourth inert atmosphere at a temperature T5 in a range of 900 °F to 1200 °F (482 °C to 649 °C), where T5 is lower than T4, (v) subject the precatalyst to a second oxidizing atmosphere at T5 for a retention time t2 in a range of 30 min to 10 h, (vi) cool in a third oxidizing atmosphere to a temperature T6 in a range of 500 °F to 700 °F (260 °C to 371 °C) to produce the activated (calcined) chromium catalyst, and (vii) purge the activated (calcined) chromium catalyst in a fifth atmosphere. Place inert solution in T6 and cool to room temperature (which is nominally 77 °F or 25 °C).

[0030] Generally, the features of this process (e.g., the pre-catalyst, the activated chromium catalyst, the oxidizing atmospheres, the inert atmospheres, the temperatures and retention times, among others) are independently described in this document and these features may be combined in any combination to further describe the disclosed process for producing an activated chromium catalyst. Furthermore, additional process steps may be performed before, during and / or after any of the steps in any of the processes disclosed in this document and may be used without limitation and in any combination to further describe these processes, unless otherwise indicated. In addition, any activated chromium catalysts produced according to the disclosed processes are within the scope of this disclosure and are covered in this document.Activated chromium catalysts may also be referred to in this document as calcined chromium catalysts.

[0031] Referring first to step (i), a precatalyst in contact with a first inert atmosphere at a temperature T1 in a range of 500 °F to 700 °F (260 °C to 371 °C). The precatalyst comprises a silica support and 0.1 to 5% by weight of chromium, 0.1 to 10% by weight of titanium and 1 to 5 mol of nitrogen / mol of titanium. Other suitable ranges for Petition 870250088394, dated 09 / 30 / 2025, p. 98 / 171 11 / 73 The amount of chromium present in the precatalyst (or in the activated chromium catalyst) includes, but is not limited to, 0.1 to 4% by weight, 0.2 to 5% by weight, 0.5 to 3% by weight, 0.5 to 2% by weight, or 0.5 to 1.5% by weight of chromium. These percentages by weight are based on the amount of chromium relative to the total weight of the precatalyst or activated chromium catalyst. Similarly, other suitable ranges of the amount of titanium present in the precatalyst (or activated chromium catalyst) include, but are not limited to, 0.5 to 10% by weight, 1 to 10% by weight, 2 to 8% by weight, or 2 to 6% by weight of titanium. These percentages by weight are also based on the amount of titanium relative to the total weight of the precatalyst or activated catalyst.

[0032] The precatalyst may also contain nitrogen from the nitrogen-containing compounds that were used to prepare the precatalyst. Generally, the precatalyst contains 1 to 5 mol of nitrogen per mol of titanium and, more frequently, 1 to 4.5, 1.5 to 5, 1.5 to 4.5, 2 to 5, 2 to 4 or 2 to 3 mol of nitrogen / mol of titanium.

[0033] The precatalyst may also be characterized by carboxylate groups / ligands that are present before activation, as well as the amount of carbon. In one aspect, the precatalyst may contain 1 to 5 moles of carboxylate per mole of titanium, in another aspect 1 to 4 moles of carboxylate / mol of titanium, in yet another aspect 1 to 3 moles of carboxylate / mol of titanium, in yet another aspect 1.5 to 5 moles of carboxylate / mol of titanium, in yet another aspect 1.5 to 4 moles of carboxylate / mol of titanium, and in yet another aspect 2 to 3 moles of carboxylate / mol of titanium. Examples of carboxylates (including dicarboxylates) include acetate, oxalate, citrate, malate, lactate, gluconate, glycolate, 2-hydroxybutyrate, glyoxylate, lactate, malate, malonate, phosphonoacetate, tartrate, and the like.

[0034] Additionally or alternatively, the precatalyst may contain 0.5 to 10% by weight of carbon before activation and, more frequently, 1 to 10% by weight, 1 to 5% by weight, 2 to 10% by weight, Petition 870250088394, dated 09 / 30 / 2025, page 99 / 171 12 / 73 from 2 to 8% by weight or from 2 to 6% by weight of carbon and similar substances. These percentages by weight are based on the amount of carbon relative to the weight of the precatalyst.

[0035] The precatalyst in step (i) – that is, the precatalyst containing the silica support, 0.1 to 5 wt% chromium, 0.1 to 10 wt% titanium and 1 to 5 mol nitrogen / mol titanium – may be subjected to the activation process alone or optionally in a blend or mixture with a second precatalyst with a different catalyst composition. Any relative amounts of the precatalyst in step (i) and the second precatalyst may be used. For example, the second precatalyst may be a chromium / silica precatalyst; alternatively, a chromium / silica-titanium cogel precatalyst; or alternatively, a chromium-silica-titanium tergel precatalyst.

[0036] The temperature T1 in step (i) varies from 500 °F to 700 °F (260 °C to 371 °C). In one aspect, T1 may be within a range of 550 °F to 650 °F (288 °C to 343 °C), and in another aspect, T1 may vary from 600 °F to 700 °F (315 °C to 371 °C), and in yet another aspect, T1 may vary from 600 °F to 650 °F (315 °C to 343 °C). These and other temperature ranges disclosed in this document are intended to cover circumstances in which the respective step in the process is carried out at a series of different temperatures, rather than at a single fixed temperature, being within the respective temperature ranges.

[0037] In step (ii), the precatalyst is subjected to cycles of a first oxidizing atmosphere at a temperature T2 in a range of 500 °F to 700 °F (260 °C to 371 °C) and a second inert atmosphere at a temperature T3 in a range of 700 °F to 900 °F (371 °C to 482 °C). The first oxidizing atmosphere causes an exothermic temperature increase from T2 to T3, thus triggering the introduction of the second inert atmosphere which results in cooling to T2. Other illustrative and representative ranges for T2 include 600 °F to 700 °F (315 °C to 371 °C), 500 °F to 650 °F (260 °C to 343 °C), Petition 870250088394, dated 09 / 30 / 2025, pp. 100 / 171 13 / 73 625 °F to 700 °F (329 °C to 371 °C) or 575 °F to 675 °F (302 °C to 357 °C) and similar, and other illustrative and representative ranges for T3 include 700 °F to 850 °F (371 °C to 454 °C), 700 °F to 800 °F (371 °C to 427 °C), 725 °F to 900 °F (385 °C to 482 °C) or 750 °F to 850 °F (399 °C to 454 °C). For example, in a first cycle, the precatalyst is subjected to the first oxidizing atmosphere at temperature T2 in the range of 500 °F to 700 °F (260 °C to 371 °C), for example, to 550 °F (288 °C). Due to exothermic reactions, the temperature increases to temperature T3 in the range of 700 °F to 900 °F (371 °C to 482 °C), such as 775 °F (413 °C), at which point the precatalyst is subjected to the second inert atmosphere, cooling the precatalyst to any suitable temperature in the temperature range T2 of 500 °F to 700 °F (260 °C to 371 °C). In a second cycle, the precatalyst is subjected to the first oxidizing atmosphere at, for example, a temperature of 625 °F (329 °C).Due to exothermic reactions, the temperature increases to temperature T3 in the range of 700 °F to 900 °F (371 °C to 482 °C), such as 750 °F (399 °C), at which point the precatalyst is subjected to a second inert atmosphere, cooling the precatalyst again to any suitable temperature in the temperature range T2 of 500 °F to 700 °F (260 °C to 371 °C). Although not linked by theory, it is believed that limiting the temperature increase in step (ii) prevents premature oxidation of chromium, while oxidizing organics and other residues present in the precatalyst.

[0038] The oxidizing atmosphere and inert atmosphere cycles are continued until the exothermic temperature increase in the first oxidizing atmosphere is less than or equal to 50 °F (28 °C) within 15 min, or until heat must be added to maintain T3 in the presence of the first oxidizing atmosphere. In some respects, step (ii) may be carried out until the exothermic temperature increase in the first oxidizing atmosphere is less than or equal to 40 °F (22 °C) within 15 min; alternatively, less than or equal to 25 °F (14 °C) in 15 min; or alternatively, less than or equal to 10 °F (6 °C) within 15 min. Although not limited to this, the number Petition 870250088394, dated 09 / 30 / 2025, pp. 101 / 171 14 / 73 of cycles in stage (ii) is usually 2 to 10, but more often, the number of cycles in stage (ii) is 2 to 6, 2 to 4, 2 to 3, 3 to 8, 3 to 5, 4 to 10, or 4 to 6.

[0039] The first oxidizing atmosphere in each cycle of step (ii) may be the same or different and may independently comprise (or consist essentially of, or consist of) oxygen, air, a mixture of oxygen and an inert gas (e.g., nitrogen), a mixture of air and an inert gas (e.g., nitrogen) and the like, as well as any combination thereof. The first oxidizing atmosphere in each cycle of step (ii) may independently contain any suitable % by volume of oxygen ranging from 1 to 100% by volume. In one aspect, the % by volume of oxygen may be from 1 to 50% by volume, while in another aspect, the % by volume of oxygen may be from 2 to 30% by volume, and in yet another aspect, the % by volume of oxygen may be from 3 to 25% by volume, and in yet another aspect, the % by volume of oxygen may be from 4 to 21% by volume.

[0040] Similar to the first oxidizing atmosphere in each cycle of step (ii), the second inert atmosphere in each cycle of step (ii) may be the same or different. Regardless, the second inert atmosphere in each cycle of step (ii) may comprise (or consist essentially of, or consist of) nitrogen, argon or a combination thereof; alternatively, nitrogen; or, alternatively, argon.

[0041] After step (ii) and the exothermic reactions have been exhausted, the pre-catalyst is heated in step (iii) in a third inert atmosphere to a temperature T4 in a range of 1000 °F to 1400 °F (538 °C to 760 °C) and the pre-catalyst is held at T4 in the third inert atmosphere for a holding time t1 in a range of 1 h to 15 h. Any suitable heating rate may be used in step (iii), such as 1 to 5 °F / min (0.6 to 3 °C / min), 1.5 to 4 °F / min (0.8 to 2.2 °C / min) or 2 to 3.5 °F / min (1 to 2 °C / min) and the like. In addition to the T4 range of 1000 °F to 1400 °F (538 °C to 760 °C), other temperature ranges may be used, such as the following non-limiting ranges: Petition 870250088394, dated 09 / 30 / 2025, pp. 102 / 171 15 / 73 from 1000 °F to 1300 °F (538 °C to 704 °C), from 1100 °F to 1400 °F (593 °C to 760 °C), from 1100 °F to 1300 °F (593 °C to 704 °C) or from 1200 °F to 1300 °F (649 °C to 704 °C) and so on.

[0042] In step (iii), the precatalyst is held at T4 in the third inert atmosphere for a retention time t1 in a range of 1 ha 15 h. Other representative and non-limiting ranges for t1 include 1 ha 8 h, 2 ha 10 h, 3 ha 15 h, 3 ha 8 h or 4 ha 6 h and similar. Although not limited by theory, it is believed that exposure to high temperature in an inert atmosphere can dehydroxylate the catalyst, but without premature oxidation of the chromium. Furthermore, it is believed that by using a relatively low temperature T4, the main attributes of the polymer, such as molecular weight distribution and low long-chain branching, can be retained.

[0043] After step (iii), the pre-catalyst is cooled in step (iv) in a fourth inert atmosphere to a temperature T5 in a range of 900°F to 1200°F (482°C to 649°C), provided that T5 is less than T4. Any suitable cooling rate may be used in step (iv), such as 1 to 4°F / min (0.6 to 2.2°C / min), 1.5 to 3.5°F / min (0.8 to 2°C / min) or 2 to 3°F / min (1 to 1.7°C / min) and the like. In addition to the T5 range of 900 °F to 1200 °F (482 °C to 649 °C), other temperature ranges may be used, such as the following non-limiting ranges: 900 °F to 1100 °F (482 °C to 593 °C), 950 °F to 1150 °F (510 °C to 621 °C), 1000 °F to 1200 °F (538 °C to 649 °C), or 1000 °F to 1100 °F (538 °C to 593 °C), and so on.

[0044] After reaching temperature T5 in the fourth inert atmosphere, the atmosphere is changed and, in step (v), the pre-catalyst is subjected to a second oxidizing atmosphere at T5 for a retention time t2 in a range of 30 min to 10 h. Generally, the retention time t2 is a period of time sufficient to form at least 30% by weight, and more frequently, at least 50% by weight, to 70% by weight, or at least 80% by weight of chromium (VI), based on the amount of chromium present in the activated chromium catalyst. In step (v), the retention time t2 can vary from 30 min to 10 h, but Petition 870250088394, dated 09 / 30 / 2025, pp. 103 / 171 16 / 73 Other representative and non-limiting ranges for t2 include 30 min to 8 h, 1 ha to 10 h, 1 ha to 8 h, 2 ha to 6 h, or 3 ha to 5 h and similar ranges. Often, there can be a balance between chromium conversion and melt index potential, since longer t2 retention times and higher temperatures can decrease the melt index potential.

[0045] In step (vi), the catalyst is cooled in a third oxidizing atmosphere to a temperature T6 in a range of 500 °F to 700 °F (260 °C to 371 °C) to produce the activated chromium catalyst. Any suitable cooling rate may be used in step (vi), such as 1 to 4 °F / min (0.6 to 2.2 °C / min), 1.5 to 3.5 °F / min (0.8 to 2 °C / min) or 2 to 3 °F / min (1 to 1.7 °C / min) and the like. In addition to the T6 range of 500 °F to 700 °F (260 °C to 371 °C), other temperature ranges may be used, such as the following non-limiting ranges: 500 °F to 650 °F (260 °C to 343 °C), 550 °F to 700 °F (288 °C to 371 °C), 550 °F to 650 °F (288 °C to 343 °C), or 600 °F to 675 °F (315 °C to 357 °C), and so on. Although not required, the T6 temperature is often within 50 °F (28 °C), within 25 °F (14 °C), or within 10 °F (6 °C) of the T1 temperature.Although not limited by theory, it is believed that switching to an inert atmosphere at a relatively high temperature could impair conversion to Cr(VI).

[0046] After step (vi), the activated (calcined) chromium catalyst is purged in step (vii) in a fifth inert atmosphere at T6 and then cooled to room temperature (which is nominally 77 °F or 25 °C). Although not limited to this, in step (vii), the activated (calcined) chromium catalyst may be purged with the fifth inert atmosphere at T6 for a purge time t3 which is typically within a range of 2 min to 20 h; alternatively, 5 min to 12 h; alternatively, 5 min to 5 h; alternatively, 15 min to 4 h; or alternatively, 30 min to 6 h. Although not limited by theory, purging in the inert atmosphere is believed to be important to remove oxygen / air from the pores of the catalyst, so as to prevent oxygen / air from acting as a poison when in the reactor during polymerization. Petition 870250088394, dated 09 / 30 / 2025, pp. 104 / 171 17 / 73

[0047] In the process for producing the activated chromium catalyst, the first inert atmosphere, the third inert atmosphere, the fourth inert atmosphere, the fifth inert atmosphere, and the sixth inert atmosphere may be the same or different. For example, in one aspect, the third inert atmosphere and the fourth inert atmosphere are the same, while in another aspect, the third inert atmosphere and the fourth inert atmosphere are different. The first inert atmosphere, the third inert atmosphere, the fourth inert atmosphere, the fifth inert atmosphere, and the sixth inert atmosphere – independently – may comprise (or consist essentially of, or consist of) nitrogen, argon, or a combination thereof; alternatively nitrogen; or alternatively argon.

[0048] Similarly, the second oxidizing atmosphere and the third oxidizing atmosphere may be the same or different. For example, in one aspect, the second oxidizing atmosphere and the third oxidizing atmosphere are the same, while in another aspect, the second oxidizing atmosphere and the third oxidizing atmosphere are different. The second oxidizing atmosphere and the third oxidizing atmosphere – independently – may comprise (or consist essentially of, or consist of) oxygen, air, a mixture of oxygen and an inert gas (e.g., nitrogen), a mixture of air and an inert gas (e.g., nitrogen), and the like, as well as any combination thereof. The second oxidizing atmosphere and the third oxidizing atmosphere may independently contain any suitable % by volume of oxygen ranging from 1 to 100% by volume.In one aspect, the percentage by volume of oxygen can be from 1 to 50% by volume, while in another aspect, the percentage by volume of oxygen can be from 2 to 30% by volume, and in yet another aspect, the percentage by volume of oxygen can be from 3 to 25% by volume, and in yet another aspect, the percentage by volume of oxygen can be from 4 to 21% by volume.

[0049] Referring again to step (i) of the processes for producing an activated chromium catalyst, a pre-catalyst is placed in contact in step (i) with a first inert atmosphere at a temperature T1 in a range of 500 °F to 700 °F (260 °C to 371 °C). Before step (i), the pre Petition 870250088394, dated 09 / 30 / 2025, pp. 105 / 171 18 / 73 catalyst can be loaded into a suitable container and then heated to T1. Thus, the processes disclosed in this document may additionally comprise, before step (i), a step of loading and heating the pre-catalyst in the first inert atmosphere to T1. Before loading, the pre-catalyst may be at any suitable temperature, but is generally at room temperature to 120 °F (49 °C), although not limited to this.

[0050] Charging the precatalyst before step (i) can be done by charging 2 to 10 portions, 2 to 8 portions, 3 to 10 portions, or 3 to 6 portions of the total amount of precatalyst in the container before step (i) is performed. The number of portions may depend on the size of the container and the amount of catalyst to be activated, among other considerations. During the charging of each portion of the total amount of precatalyst, the temperature is generally maintained in a range of 300 to 600 °F (149 °C to 315 °C), such as 400 to 600 °F (204 °C to 315 °C). Often, the loading of each portion of the total amount of precatalyst is stopped when the temperature drops below 400 °F (204 °C), or below 300 °F (149 °C), typically as a result of water evaporation.Additionally or alternatively, the loading of each portion of the total amount of precatalyst can be stopped when the pressure increases above 1 psig, again largely as a result of water evaporation (i.e., steam).

[0051] Although not limited to this, the total charge or total quantity of the pre-catalyst may be at least 100 lb, at least 200 lb, at least 300 lb, at least 500 lb, at least 750 lb, at least 1000 lb, at least 1200 lb or at least 1500 lb, and frequently up to and including 1750 lb, 2000 lb or 2500 lb.

[0052] In this document, the processes for producing activated chromium catalysts can be carried out in any suitable calcination or activation vessel, but frequently the processes are carried out in Petition 870250088394, dated 09 / 30 / 2025, pp. 106 / 171 19 / 73 A fluidized bed vessel, or any one or more steps in the processes, may be conducted in a fluidized bed vessel. The fluidized bed vessel may be operated in batches or continuously, or any one or more steps in the processes may be conducted in batches or continuously. Catalyst quantities and bed depths may be any that are suitable for fluidized bed operation. In processes for producing activated chromium catalysts, the pre-catalyst (or the activated catalyst) may be brought into contact with a gas stream at any suitable linear velocity, generally in the range of 0.05 to 0.6 ft / s.For example, each step in the disclosed processes can be performed by fluidizing the pre-catalyst (or the activated catalyst, as the context requires) in an inert fluidizing gas (for an inert atmosphere) or a fluidizing gas containing oxygen (for an oxidizing atmosphere) at a linear gas stream velocity – independently – within a range of 0.05 to 0.6 ft / s in some respects, 0.05 to 0.3 ft / s or 0.1 to 0.4 ft / s in other respects, 0.2 to 0.5 ft / s, 0.2 to 0.4 ft / s or 0.2 to 0.3 ft / s.

[0053] Although not limited to this, the diameter of the fluidized bed vessel may be at least 12 in, at least 20 in, at least 30 in, at least 40 in or at least 50 in and often up to and including 55 in, 60 in or 70 in.

[0054] The activated catalyst produced from the disclosed activation processes has many properties that are superior to those of otherwise identical catalysts that have not been subjected to the specific steps described above in this document. For example, the activated catalyst consistent with this invention may have a higher melting index potential (e.g., at least 10% higher, at least 25% higher, at least 50% higher, at least 75% higher, or at least 100% higher) than that of an otherwise identical catalyst (often referred to as a control catalyst) activated by exposure to an oxidizing atmosphere at a temperature T4 for a holding time of t1. Alternatively, the catalyst Petition 870250088394, dated 09 / 30 / 2025, pp. 107 / 171 20 / 73 control can be the Magnapore® catalyst, which is commercially available from WR Grace, when calcined at a temperature of 1200 °F (649 °C) for a period of 3 h (for laboratory scale) or 8 h (for large scale). When making these comparisons, it is necessary that the polymerization reaction be conducted under the same conditions. That is, the reaction temperature must be identical, and the concentration of ethylene and comonomer in the reaction zone must also be equal, and the productivity achieved must be equal, preferably in the range of 3000 gPE / gCat to 5000 gPE / gCat.

[0055] This enhanced melting index potential can be measured by means of melting index (MI, I2), or high-charge melting index (HLMI, I21), or both. As an example, the activated catalyst of the present invention may have a potential MI of at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1 or at least 1.2 g / 10 min. Additionally or alternatively, the activated catalyst of the present invention, when tested in isobutane at 105 °C, 550 psig of ethylene at 3000 gPE / gCat, may have an HLMI potential of at least 20, at least 25, at least 30, at least 35, at least 40, at least 50, at least 60, at least 70, at least 80 or at least 100 g / 10 min.

[0056] Although the activated catalysts described in this document may offer significant improvements in melt index potential, the polymer produced can often be very similar to that produced with a control catalyst. In some respects, therefore, the activated catalyst consistent with this invention can produce a polymer under standard polymerization conditions with an Mw / Mn ratio (or an Mz / Mw ratio, or a CY-a parameter) that is within 35% (or within 30%, within 25%, within 20%, within 15%, within 10%, or within 5%) of the Mw / Mn (or the Mz / Mw, or the CY-a parameter) of a polymer produced using a control catalyst as defined above. Standard polymerization conditions are detailed in the examples below, but Petition 870250088394, dated 09 / 30 / 2025, pp. 108 / 171 21 / 73 briefly, isobutane diluent, polymerization temperature of 105 °C, ethylene pressure of 550 psig, for a time necessary to achieve a productivity of 3000 g of polymer per g of catalyst.

[0057] Additionally or alternatively, the activated catalyst consistent with this invention may produce a polymer under standard polymerization conditions with a Mw that is 30% lower than (or 25% lower than, 20% lower than, 15% lower than, or 10% lower than) the Mw of a polymer produced using a control catalyst as defined above, when compared at the same or substantially the same MI (or HLMI), as the context requires.

[0058] Unexpectedly, the activated catalyst consistent with this invention can produce polymers with lower amounts of gels. In one aspect, the activated catalyst can produce a polymer under standard polymerization conditions that has a total film gel count (or a catalyst particle gel count) less than or equal to 100 gels per ft² of 25 micron thick film (and in some cases, less than or equal to 80, or less than or equal to 60, or less than or equal to 40, or less than or equal to 30, or less than or equal to 20, or less than or equal to 10, or less than or equal to 8, or less than or equal to 5 gels per ft² of 25 micron thick film), wherein the film gels encompass a size (diameter) greater than 200 µm (and caused by catalyst particles for the catalyst particle gel count).

[0059] Generally, the disclosed processes are applicable to the activation of any supported chromium precatalyst comprising a silica support, thereby forming the activated chromium catalyst with at least a portion of the chromium in a hexavalent oxidation state. Thus, the supported chromium precatalysts contemplated in this document encompass those prepared by placing a silica support in contact with a chromium-containing compound (a chromium precursor, a chromium source) and Petition 870250088394, dated 09 / 30 / 2025, pp. 109 / 171 22 / 73 a titanium-containing compound (a titanium precursor, a titanium source). The precatalyst may often be referred to as a chromium / titanium-containing silica precatalyst. The precatalyst can be formed by depositing a water-soluble titanium compound and a water-soluble chromium compound onto a pre-formed silica in an aqueous flow paste, then spray-drying the flow paste to form the precatalyst. The precatalyst can also be formed by depositing a water-soluble titanium compound onto a pre-formed silica already containing the necessary chromium in an aqueous flow paste, then spray-drying the flow paste to form the precatalyst.

[0060] Although not limited to this, typical titanium compounds include titanium carboxylates, which may also contain a nitrogen compound to help adjust the pH. Carboxylates can be dicarboxylic or tricarboxylic acids and alpha-hydroxy monocarboxylic acids, examples of which include oxalic acid, citric acid, malic acid, lactic acid, glycolic acid, gluconic acid, 2-hydroxybutyric acid, glyoxylic acid, malonic acid, phosphonoacetic acid, tartaric acid, and the like. Suitable nitrogen compounds include simple alkylamines, alkanolamines, cyclic amines, and more complex multi-nitrogen compounds, as well as amides and quaternary ammonium hydroxides.Examples include dimethylformamide (DMF), acetamide, acrylamide, allylamine, ammonia, methylamine, diethylamine, ethanolamine, diethanolamine, butylamine, tert-butylamine, N,N'-dibutyl urea, tetraethylammonium hydroxide, ammonium hydroxide, dimethylethanolamine, creatine, creatinine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), diethylhydroxyamine, diisopropanolamine, dimethylaminoethanol, dimethyl carbamate, dimethylformamide, dimethylglycine, dimethylisopropanolamine, N,N'-dimethylurea, ethylamine, glycolamine, hexylamine, hydroxyamine, imidazole, isopropanolamine, methacrylamide, N-methylaniline, N-methyl-2-propanolamine, methyldiethanolamine, methylformamide, propylamine, 2-propanolamine, pyrazole, pyrrolidine, pyrrolidinone, succinimide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, triethanolamine, tri. Petition 870250088394, dated 09 / 30 / 2025, pp. 110 / 171 23 / 73 isopropanolamine, trimethylamine, urea and the like. Typical chromium compounds include chromium(III) acetate, basic chromium(III) acetate, chromium(III) formate, C2O3, Cr(OH)3, Cr(NO3)3 and the like. Generally, the chromium compound is a trivalent compound, although hexavalent chromium compounds are also suitable, but only if they are then reduced to the trivalent form during catalyst manufacturing. The silica used in this invention can be any suitable pre-formed silica xerogel having acceptable porosity, with grades available from Asahi Glass and Grace (e.g., HA30W). Although not limited to this, silicas with BET surface areas of 300 to 500 m2 / g, pore volumes of 1.5 to 2.0 m2 / g (e.g., approximately 1.6 mL / g) and average d50 particle sizes of 30 to 130 microns (e.g., 40 to 70 microns) are conveniently used.Additional information regarding precatalysts that can be activated as described in this document and methods for preparing precatalysts are provided in U.S. Representative Patents Nos. 10,300,460, 10,323,109, 10,513,570, 10,543,480, 10,722,874, 10,858,456, 10,889,664 and 11,242,416.

[0061] Chromium polymerization catalysts generally require supports with relatively high porosity in order to allow for catalyst fragmentation and subsequent release of polymer chains from fragments, a portion of these chains being hundreds of times longer than the diameter of the pores in the catalyst. Thus, the total pore volume of the precatalyst (either the silica support or the activated chromium catalyst) is frequently within a range of 0.5 to 5 mL / g, more frequently 1 to 5 mL / g, 1 to 3 mL / g or similar 1.5 to 2 mL / g. The BET surface area of ​​the precatalyst (or silica support or activated chromium catalyst) is not limited to any particular range, but is generally in a range of 100 to 700 m² / g, such as 200 to 600 m² / g, 250 to 550 m² / g or 300 to 500 m² / g and similar ranges.

[0062] The pre-catalyst, silica support and activated chromium catalyst may have any suitable shape or form, and such may Petition 870250088394, dated 09 / 30 / 2025, pp. 111 / 171 24 / 73 depends on the type of polymerization process in which the chromium catalyst is used. Generally, however, the precatalyst, silica support, and activated chromium catalyst have a relatively small particle size, in which representative ranges for the average particle size (d50) of the precatalyst (or silica support or activated chromium catalyst) may include 10 to 500 microns, 15 to 250 microns, 30 to 130 microns, or 40 to 70 microns, although not limited to these.

[0063] Similarly, the amount of chromium in an oxidation state of +5 or less in the precatalyst (before activation) is not particularly limited. The amount of chromium in the precatalyst in an oxidation state of +5 or less is typically at least 50% by weight and, more frequently, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, or at least 95% by weight. This percentage is based on the amount of chromium in the precatalyst in an oxidation state of +5 or less relative to the total amount of chromium in the precatalyst.

[0064] On the other hand, at least 40% by weight of the chromium in the activated chromium catalyst is present in a hexavalent oxidation state after the activation step and, more frequently, at least 50% by weight is present as chromium (VI). In additional aspects, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, or at least 95% by weight of the chromium in the activated chromium catalyst may be present in a +6 oxidation state. These weight percentages are based on the total amount of chromium present in the activated chromium catalyst. Traditional chromium (VI) catalysts will often have an orange, yellow, or brown color, indicating the presence of chromium (VI). POLYMERIZATION PROCESSES

[0065] Olefin polymers (e.g., ethylene polymers) can be produced from activated chromium catalysts using Petition 870250088394, dated 09 / 30 / 2025, pp. 112 / 171 25 / 73 any suitable olefin polymerization process using various types of polymerization reactors, polymerization reactor systems and polymerization reaction conditions. Such a polymerization process may comprise (I) carrying out any process to produce the activated chromium catalyst disclosed in this document and (II) bringing the activated chromium catalyst and an optional cocatalyst into contact with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer. This invention also encompasses any olefin polymers (e.g., ethylene polymers) produced by any of the polymerization processes disclosed in this document.

[0066] In polymerization processes, a cocatalyst may be used with the activated chromium catalyst. In one aspect, the cocatalyst may comprise an aluminoxane compound, an organoaluminum compound, or an organoboron compound, and this includes combinations of more than one cocatalyst compound. Representative and non-limiting examples of aluminoxanes include methylaluminoxane, modified methylaluminoxane, ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane, n-butylaluminoxane, t-butylaluminoxane, sec-butylaluminoxane, isobutylaluminoxane, 1-pentylaluminoxane, 2-pentylaluminoxane, 3-pentylaluminoxane, isopentylaluminoxane, neopentylaluminoxane and the like, or any combination thereof.Representative and non-limiting examples of organoaluminum compounds include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, tri-isobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, di-isobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminum chloride and the like, or any combination thereof. Representative and non-limiting examples of organoborane compounds include tri-n-butylborane, tripropylborane, triethylborane and the like, or any combination thereof. Cocatalysts that may be used are not limited to the cocatalysts described above. Other suitable catalysts (such as organomagnesium and organolithium) are also acceptable. Petition 870250088394, dated 09 / 30 / 2025, pp. 113 / 171 26 / 73 known to those skilled in the art, including, for example, those disclosed in U.S. Patent Nos. 3,242,099, 4,794,096, 4,808,561, 5,576,259, 5,807,938, 5,919,983, 7,294,599, 7,601,665, 7,884,163, 8,114,946 and 8,309,485.

[0067] As used in this document, a polymerization reactor includes any polymerization reactor capable of polymerizing olefin monomers and comonomers (one or more than one comonomer) to produce homopolymers, copolymers, terpolymers, and the like. The various types of polymerization reactors include those that may be referred to as a batch reactor, fluidized paste reactor, gas-phase reactor, solution reactor, high-pressure reactor, tubular reactor, autoclave reactor, and the like, or combinations thereof; or alternatively, the polymerization reactor system may comprise a fluidized paste reactor, a gas-phase reactor, a solution reactor, or a combination thereof. The polymerization conditions for the various types of reactors are well known to those skilled in the art. Gas-phase reactors may comprise fluidized bed reactors or horizontal stacked reactors.Fluid paste reactors comprise vertical or horizontal circuits. High-pressure reactors may comprise autoclave or tubular reactors. Reactor types may include batch or continuous processes. Continuous processes may use intermittent or continuous product discharge. Polymerization reactor systems and processes may also include partial or total direct recycling of unreacted monomer, unreacted comonomer, and / or diluent.

[0068] A polymerization reactor system may comprise a single reactor or multiple reactors (2 reactors, more than 2 reactors, etc.) of the same type or of different types. For example, the polymerization reactor system may comprise a fluid paste reactor, a gas-phase reactor, a solution reactor, or a combination of two or more of these reactors. Polymer production in multiple reactors may include several stages in at least two separate polymerization reactors interconnected by a transfer device that makes it possible to Petition 870250088394, dated 09 / 30 / 2025, pp. 114 / 171 27 / 73 Transfer the resulting polymers from the first polymerization reactor to the second reactor. The desired polymerization conditions in one reactor may differ from the operating conditions of the other reactors. Alternatively, multi-reactor polymerization may include the manual transfer of polymer from one reactor to subsequent reactors for continuous polymerization. Multi-reactor systems may include any combination including, but not limited to, multiple closed-loop reactors, multiple gas-phase reactors, a combination of closed-loop and gas-phase reactors, multiple high-pressure reactors, or a combination of high-pressure closed-loop and / or gas-phase reactors. The multiple reactors may operate in series, in parallel, or both.Consequently, the present invention encompasses polymerization reactor systems comprising a single reactor, comprising two reactors, and comprising more than two reactors. The polymerization reactor system may comprise a fluid paste reactor, a gas phase reactor, a solution reactor, in certain aspects of this invention, as well as combinations of multiple reactors thereof.

[0069] According to one aspect, the polymerization reactor system may comprise at least one closed-loop fluidized slurry reactor comprising vertical or horizontal circuits. The monomer, diluent, catalyst, and comonomer may be continuously fed into a closed-loop reactor where polymerization occurs. Generally, continuous processes may comprise the continuous introduction of the monomer / comonomer, a catalyst, and a diluent into a polymerization reactor and the continuous removal from this reactor of a suspension comprising polymer and diluent particles. The reactor effluent may be flash-evaporated to remove the solid polymer from the liquids comprising the diluent, monomer, and / or comonomer. Various technologies may be used for this separation step including, but not limited to, flash-evaporation which may include any combination of Petition 870250088394, dated 09 / 30 / 2025, pp. 115 / 171 28 / 73 addition of heat and reduction of pressure, separation by cyclonic action in a cyclone or hydrocyclone, or separation by centrifugation.

[0070] A typical fluid paste polymerization process (also known as the particle-forming process) is disclosed, for example, in U.S. Patent Nos. 3,248,179, 4,501,885, 5,565,175, 5,575,979, 6,239,235, 6,262,191, 6,833,415 and 8,822,608. Suitable diluents used in fluid paste polymerization include, but are not limited to, the monomer being polymerized and hydrocarbons that are liquid under reaction conditions. Examples of suitable diluents include, but are not limited to, hydrocarbons such as propane, cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane and n-hexane. Some closed-loop polymerization reactions can occur under bulk conditions, where no diluent is used.

[0071] According to yet another aspect, the polymerization reactor system may comprise at least one gas-phase reactor (e.g., a fluidized bed reactor). Such reactor systems may employ a continuous recycle stream containing one or more monomers continuously cycled through a fluidized bed in the presence of the catalyst under polymerization conditions. A recycle stream may be withdrawn from the fluidized bed and recycled back into the reactor. Simultaneously, the polymer product may be withdrawn from the reactor and new or fresh monomer may be added to replace the polymerized monomer.Such gas-phase reactors may comprise a process for the multi-stage gas-phase polymerization of olefins, wherein the olefins are polymerized in the gas phase in at least two independent gas-phase polymerization zones by feeding a catalyst-containing polymer formed in a first polymerization zone into a second polymerization zone. Representative gas-phase reactors are disclosed in U.S. Patents Nos. 5,352,749, 4,588,790, 5,436,304, 7,531,606 and 7,598,327.

[0072] According to yet another aspect of the invention, the system Petition 870250088394, dated 09 / 30 / 2025, pp. 116 / 171 29 / 73 of a polymerization reactor may comprise a high-pressure polymerization reactor, for example, it may comprise a tubular reactor or an autoclave reactor. Tubular reactors may have several zones where fresh monomer, initiators or catalysts are added. The monomer may be entrained in an inert gas stream and introduced into one zone of the reactor. Initiators, catalysts and / or catalyst components may be entrained in a gas stream and introduced into another zone of the reactor. The gas streams may be intermixed for polymerization. Heat and pressure may be appropriately employed to obtain ideal polymerization reaction conditions.

[0073] According to yet another aspect, the polymerization reactor system may comprise a solution polymerization reactor in which the monomer / comonomer is brought into contact with the catalyst by stirring or other suitable means. A carrier comprising an inert organic diluent or excess monomer may be employed. If desired, the monomer / comonomer may be brought into contact with the catalytic reaction product in the presence or absence of liquid material in the vapor phase. The polymerization zone may be maintained at temperatures and pressures that will result in the formation of a polymer solution in a reaction medium. Stirring may be employed to obtain better temperature control and to maintain uniform polymerization mixtures throughout the polymerization zone. Suitable means are used to dissipate the exothermic heat of polymerization.

[0074] The polymerization reactor system may further comprise any combination of at least one raw material feed system, at least one feed system for the catalyst or catalyst components and / or at least one polymer recovery system. Suitable reactor systems may further comprise systems for raw material purification, catalyst storage and preparation, extrusion, reactor cooling, polymer recovery, Petition 870250088394, dated 09 / 30 / 2025, pp. 117 / 171 30 / 73 Fractionation, recycling, storage, unloading, laboratory analysis, and process control. Depending on the desired properties of the olefin polymer, hydrogen can be added to the polymerization reactor as needed (e.g., continuously or pulsed).

[0075] The polymerization conditions that are controlled for efficiency and to provide the desired polymer properties may include temperature, pressure, and the concentrations of various reagents. The polymerization temperature can affect catalyst productivity, polymer molecular weight, and molecular weight distribution. Several polymerization conditions can be kept substantially constant, for example, for the production of a particular grade of olefin polymer (or ethylene polymer). A suitable polymerization temperature can be any temperature below the depolymerization temperature according to the Gibbs free energy equation. Typically, this includes 60 °C to 280 °C, for example, or 60 °C to 120 °C, depending on the type of polymerization reactors. In some reactor systems, the polymerization temperature may generally be within a range of 70 °C to 105 °C or 75 °C to 100 °C.

[0076] The appropriate pressures will also vary depending on the reactor and the type of polymerization. The pressure for liquid-phase polymerizations in a closed-loop reactor is typically less than 1000 psig (6.9 MPa). The pressure for gas-phase polymerization is generally 200 to 500 psig (1.4 MPa to 3.4 MPa). High-pressure polymerization in tubular or autoclave reactors is generally performed at 20,000 psig to 75,000 psig (138 MPa to 517 MPa). Polymerization reactors can also be operated in a supercritical region, generally occurring at higher temperatures and pressures. Operation above the critical point of a pressure / temperature diagram (supercritical phase) can offer advantages to the polymerization reaction process.

[0077] Olefin monomers that can be used with the Petition 870250088394, dated 09 / 30 / 2025, pp. 118 / 171 31 / 73 Chromium catalysts and polymerization processes of this invention may include olefin compounds with 2 to 30 carbon atoms per molecule and with at least one olefinic double bond, such as ethylene or propylene. In one aspect, the olefin monomer may comprise a C2-C20 olefin; alternatively, a C2-C20 alpha-olefin; alternatively, a C2-C10 olefin; alternatively, a C2-C10 alpha-olefin; alternatively, the olefin monomer may comprise ethylene; or alternatively, the olefin monomer may comprise propylene (for example, to produce a polypropylene homopolymer or a propylene-based copolymer).

[0078] When a copolymer (or alternatively, a terpolymer) is desired, the olefin monomer and the olefin comonomer may independently comprise, for example, a C2-C20 alpha-olefin. In some aspects, the olefin monomer may comprise ethylene or propylene, which is copolymerized with at least one comonomer (for example, a C2-C20 alpha-olefin or a C3-C20 alpha-olefin). According to one aspect of this invention, the olefin monomer used in the polymerization process may comprise ethylene.In this respect, the comonomer may comprise a C3-C10 alpha-olefin; alternatively, the comonomer may comprise 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, styrene, or any combination thereof; alternatively, the comonomer may comprise 1-butene, 1-hexene, 1-octene, or any combination thereof; alternatively, the comonomer may comprise 1-butene; alternatively, the comonomer may comprise 1-hexene; or alternatively, the comonomer may comprise 1-octene.

[0079] In one aspect, the polymerization process can be carried out at a productivity of 2000 to 5000 g of polymer per gram of catalyst and / or at a space-time yield greater than or equal to 2, 2.5, 2.8, 3 or 4 (lb / h) / gal and / or less than or equal to 6, 5.5 or 5 (lb / h) / gal, in a commercial closed-loop reactor that produces at least one ethylene / 1-hexene copolymer with a density of 0.947 g / cc, as determined by ISO Petition 870250088394, dated 09 / 30 / 2025, pp. 119 / 171 32 / 73 1183 part 2. The yield of spacetime can be within a range of any minimum value to any maximum value listed above, therefore representative and non-limiting ranges for the yield of spacetime include 2 to 6, 2 to 5, 2.5 to 5.5, 2.8 to 6, 3 to 6, 3 to 5.5, 4 to 6 or 4 to 5 (lb / h) / gal.

[0080] In another aspect, the polymerization process can be carried out at a productivity of 2000 to 5000 g of polymer per gram of catalyst and / or at a space-time yield greater than or equal to 2, 2.5, 2.8, 3 or 4 (lb / h) / gal and / or less than or equal to 6, 5.5 or 5 (lb / h) / gal, in a commercial closed-loop reactor that produces at least one ethylene / 1-hexene copolymer with a density of 0.938 g / cc, as determined by ISO 1183 part 2. As above, the space-time yield can be within a range from any minimum value to any maximum value listed above and therefore representative and non-limiting ranges for space-time yield include 2 to 6, 2 to 5, 2.5 to 5.5, 2.8 to 6, 3 to 6, 3 to 5.5, 4 to 6 or 4 to 5 (lb / h) / gal. Ethylene polymers and olefin polymers

[0081] This invention is also directed to, and encompasses, olefin polymers produced using any of the chromium catalysts and polymerization processes disclosed in this document. The olefin polymers covered in this document may include any polymer produced from any olefin monomer and optional comonomers described in this document. For example, the olefin polymer may comprise an ethylene homopolymer, an ethylene copolymer (e.g., ethylene / α-olefin, ethylene / 1-butene, ethylene / 1-hexene, ethylene / 1-octene, etc.), a propylene homopolymer, a propylene copolymer, an ethylene terpolymer, a propylene terpolymer, and the like, including any combinations thereof. In one aspect, the olefin polymer may comprise an ethylene homopolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, and / or an ethylene / 1-octene copolymer. Petition 870250088394, dated 09 / 30 / 2025, pp. 120 / 171 33 / 73 while in another aspect, the olefin polymer may comprise an ethylene / 1-hexene copolymer.

[0082] If the resulting polymer produced according to the present invention is, for example, an ethylene polymer, its properties can be characterized by various analytical techniques known and used in the polyolefin industry. The manufactured articles can be formed from, and / or may comprise, the olefin polymers (e.g., ethylene polymers) of this invention, whose typical properties are given below.

[0083] An illustrative and non-limiting example of a first ethylene polymer (e.g., an ethylene / α-olefin copolymer) produced using the activated chromium catalysts disclosed in this document – ​​may have a high-charge melt index (HLMI) in the range of 10 to 80 g / 10 min, a density in the range of 0.93 to 0.96 g / cm3 and a total film gel count of less than or equal to 100 gels per ft2 of 25 micron thick film (or less than or equal to 80, or less than or equal to 60, or less than or equal to 40, or less than or equal to 30, or less than or equal to 20, or less than or equal to 10, or less than or equal to 8, or less than or equal to 5 gels per ft2 of 25 micron thick film), wherein the film gels encompass a size larger than 200 pm.Alternatively, the gel count of gels >200 microns that are caused by non-fragmented catalyst particles (e.g., non-fragmented Cr / silica catalyst particles) may be less than or equal to 100 gels per ft² of 25-micron thick film, or less than or equal to 80, or less than or equal to 60, or less than or equal to 40, or less than or equal to 30, or less than or equal to 20, or less than or equal to 10, or less than or equal to 8, or less than or equal to 5 gels per ft² of 25-micron thick film. The ethylene polymer contains a total (disintegrated and non-fragmented) of 150 to 680 ppm of silica, 1.5 to 6.8 ppm of chromium, and 1.5 to 40 ppm of titanium. Petition 870250088394, dated 09 / 30 / 2025, pp. 121 / 171 34 / 73

[0084] An illustrative and non-limiting example of a second ethylene polymer (e.g., an ethylene / α-olefin copolymer) may have a melt index (MI) in the range of 0.1 g / 10 min to 1 g / 10 min, a density in the range of 0.93 to 0.96 g / cm3 and a total film gel count (or a catalyst particle gel count) less than or equal to 100 gels per ft2 of 25 micron thick film (or less than or equal to 80, or less than or equal to 60, or less than or equal to 40, or less than or equal to 30, or less than or equal to 20, or less than or equal to 10, or less than or equal to 8, or less than or equal to 5 gels per ft2 of 25 micron thick film), wherein the film gels encompass a size greater than 200 µm (and may be caused by unfragmented catalyst particles for catalyst particle gel count).The ethylene polymer contains 150 to 680 ppm of silica, 1.5 to 6.8 ppm of chromium, and 1.5 to 40 ppm of titanium.

[0085] Furthermore, these first and second illustrative ethylene polymers (which are typically in the form of pellets or granules) consistent with the present invention may also have any of the polymer properties listed below and in any combination, unless otherwise indicated.

[0086] The density of ethylene-based polymers can often vary from 0.93 to 0.96 or from 0.93 to 0.956 g / cm3. In one aspect, the density can vary from 0.934 to 0.96, from 0.934 to 0.956 in another aspect, from 0.934 to 0.95 in yet another aspect, or from 0.945 to 0.958 g / cm3 in yet another aspect.

[0087] Ethylene polymers can have a variety of melt flow properties, as indicated by the high-load melt index (HLMI) in a range of 10 to 80 g / 10 min. In some respects, the HLMI of ethylene polymers may be in a range of 10 to 70, 10 to 60, 10 to 50, 20 to 80, 20 to 50, or 30 to 50 g / 10 min and similar ranges. Additionally or alternatively, these ethylene polymers may have a melt index (MI) Petition 870250088394, dated 09 / 30 / 2025, pp. 122 / 171 35 / 73 from 0.1 to 1 g / 10 min and, more frequently, from 0.1 to 0.75, from 0.1 to 0.6, from 0.2 to 1, from 0.2 to 0.6 or from 0.3 to 0.6 g / 10 min and similar.

[0088] In one aspect, ethylene polymers can have a Mw in the range of 100,000 to 250,000, 120,000 to 200,000, or 140,000 to 180,000 g / mol. For example, Mw can be less than or equal to 180,000, less than or equal to 170,000, or less than or equal to 160,000 g / mol. Additionally or alternatively, the ethylene polymer can have a Mn of 3,000 to 25,000, 8,000 to 20,000, 10,000 to 18,000, or 12,000 to 15,000 g / mol. For example, Mn can be less than or equal to 15,000, less than or equal to 14,000, or less than or equal to 13,000 g / mol. Additionally or alternatively, ethylene polymers can have an Mz of 500,000 to 2,000,000, 500,000 to 1,800,000, or 600,000 to 1,500,000 g / mol. For example, Mz can be less than or equal to 1,300,000, less than or equal to 1,100,000, or less than or equal to 1,000,000 g / mol.Although not limited to this, these ethylene polymers can have an Mw / Mn ratio in a range of 7 to 20, such as 8 to 18, 9 to 17, 9 to 15, or 10 to 14. For example, Mw / Mn can be less than or equal to 14, less than or equal to 13, less than or equal to 12.5, or less than or equal to 11.5. Similarly, representative ranges for the Mz / Mw ratio include 5 to 10, 5 to 9, 6 to 10, or 6 to 9. For example, Mz / Mw can be less than or equal to 8, less than or equal to 7.5, less than or equal to 7, less than or equal to 6.5, or less than or equal to 6.

[0089] Additionally or alternatively, these ethylene polymers may have a CY-a parameter of 0.1 to 0.3 in one aspect, 0.13 to 0.2 in another aspect, 0.13 to 0.17 in another aspect, 0.16 to 0.26 in another aspect, 0.17 to 0.24 in yet another aspect, and 0.18 to 0.22 in yet another aspect. For example, the CY-a parameter may be less than or equal to 0.18, less than or equal to 0.17, less than or equal to 0.165, less than or equal to 0.16, less than or equal to 0.155, or less than or equal to 0.15. This rheological parameter is determined from viscosity data. Petition 870250088394, dated 09 / 30 / 2025, pp. 123 / 171 36 / 73 measured at 190 °C and using the Carreau-Yasuda (CY) empirical model described in this document.

[0090] Furthermore, ethylene polymers are produced with a supported activated chromium catalyst, as discussed in this document. Ziegler-Natta and metallocene-based catalyst systems are not required. Therefore, ethylene polymers cannot contain any measurable amount of zirconium or hafnium or vanadium or magnesium (catalyst residue), i.e., less than 0.1 ppm by weight. In some respects, ethylene polymers may independently contain less than 0.08 ppm, less than 0.05 ppm, or less than 0.03 ppm of zirconium (or hafnium, or vanadium, or magnesium). The quantities of these elements can be determined by ICP analysis on a PerkinElmer Optima 8300 instrument. Polymer samples can be burned in a Thermolyne furnace with sulfuric acid overnight, followed by acid digestion in a HotBlock with HCl and HNO3 (3:1 v:v).

[0091] Instead, ethylene polymers typically contain 1.5 to 6.8 ppm of chromium, 1.5 to 40 ppm of titanium, and 150 to 680 ppm of silica (by weight). Other illustrative ranges for the chromium content of these ethylene polymers include, but are not limited to, 1.8 to 6 ppm, 2 to 6.8 ppm, 2 to 6 ppm, 2 to 5 ppm, 2 to 4.5 ppm, 2 to 4 ppm, 1.5 to 6 ppm, 1.5 to 5.5 ppm, 1.5 to 5 ppm, or 3 to 6 ppm of chromium. Other illustrative ranges for the titanium content of these ethylene polymers include, but are not limited to, 1.5 to 30 ppm, 2 to 40 ppm, 2 to 30 ppm, 2 to 10 ppm, 3 to 30 ppm, 3 to 20 ppm, 3 to 10 ppm, 4 to 20 ppm, 5 to 40 ppm, 5 to 25 ppm, 5 to 15 ppm, 7 to 17 ppm, or 8 to 16 ppm of titanium. The amounts of these elements can be determined by ICP analysis on a PerkinElmer Optima 8300 instrument.Other illustrative ranges for the silica content of these ethylene polymers include, but are not limited to, 180 to 600 ppm, 200 to 680 ppm, 200 to 600 ppm, 200 to 500 ppm, 200 to 400 ppm, 150 to 600 ppm, 150 to 500 ppm, or 150 to 450 ppm of silica. The silica content of... Petition 870250088394, dated 09 / 30 / 2025, pp. 124 / 171 37 / 73 polymer is quantified by an ASTM ash test, as discussed below.

[0092] Gel count quantities can be based on the total film gel count (all film defects larger than 200 microns in diameter) or the catalyst particle gel count (film defects larger than 200 microns in diameter that are caused by catalyst particles) of the number of gels per ft² of 25-micron thick ethylene polymer film. Most gels in chromium-derived polymers are catalyst particle gels (hard gels) that arise from the supported catalyst particle. When these supported chromium catalysts are used to polymerize ethylene, most of the catalyst particles are broken or disintegrated into imperceptibly small fragments that are dispersed in the final polymer, causing no problems, especially in thin-film products.However, depending on the polymerization conditions, some catalyst particles may be ejected from the reactor before becoming active and therefore before being disintegrated by polymerization. These unfragmented catalyst particles can result in visual imperfections on the surface of the final product or article, generally called gels or hard gels or catalyst gels, and film grades are especially sensitive to this problem (notably, such catalyst particle gels can also create noticeable defects on the surfaces of thick parts, resulting in poor surface aesthetics of the final product or article, and such surface roughness can also interfere with printing operations). Consequently, polymer film grades typically have a hard manufacturing specification on gels larger than 200 microns in diameter.During polymer manufacturing, the polymer is formed into a 25-micron thick film, and the number of gels is automatically measured by an in-line camera specially designed to count gels larger than 200 microns. The total gel count includes... Petition 870250088394, dated 09 / 30 / 2025, pp. 125 / 171 38 / 73 catalyst particle gels, as well as gels due to contamination by foreign material, or polymer particles or additive particles, for example.

[0093] Normally, to qualify as a gel, the optical imperfection recognized by the camera and computer in the gel analyzer must register the gel size as greater than 200 µm in diameter. From experience, catalyst particles of 100+ µm in diameter generally register as gels of 200+ µm, due to the polymer sometimes clinging to the catalyst particle, thus adding to its size, and also because of the lens effect, in which the catalyst particle appears magnified by the lens-shaped polymer coating. The latter is an optical magnification of the catalyst particle size due to the formation of a convex lens made of transparent polymer surrounding the catalyst particle. Thus, catalyst particle gels can be reduced by minimizing catalyst particles of 100 µm or more in size in the ethylene polymer.

[0094] Another unexpected benefit of ethylene polymers produced using supported chromium catalysts – activated as described in this document – ​​is the improved processability compared to polymers produced with conventionally activated chromium catalysts (control or comparative examples discussed further below). In extrusion processing for blown film, tubing, blow molding, and other converting applications, the extrusion pressure can be reduced by at least 3%, at least 5%, at least 8%, or at least 10%, or at least 15%, and in some cases, up to 20% or more. This improved processability can be measured or quantified in a pelletizing extruder that forms the ethylene polymer into pellets or granules, or in an extruder that is used to produce film. Consequently, the same applies to pelletizing during the manufacture of the polymers of the invention.Again, the extrusion pressure can be reduced. Petition 870250088394, dated 09 / 30 / 2025, pp. 126 / 171 39 / 73 in at least 3%, 5%, 8%, 10% or 15%, or even 20%, or more.

[0095] Similarly, the melting temperature during extrusion, during molding, during pelletizing, etc., is often lower with the polymers of the invention. The extrusion melting temperature can typically drop by at least 5, 8, 10, 15, or 20, or even 25 °F (3, 4, 6, 8, or 11, or even 14 °C), or more. And the energy consumption, as measured by the amperage to the extruder, is also reduced during the respective extrusion process compared with a polymer made from a control catalyst. This can typically be at least 5%, or at least 8%, or 10%, or 12%, or 15% lower. Furthermore, the specific energy, or processing imparted to the polymer, can be reduced by at least 1%, or 2%, or 3%, or 4%.

[0096] Another benefit of the polymers made by the catalysts of this invention is that they can often exhibit enhanced mixing during extrusion. This is evidenced by a greater drop in the melt index as they pass through the extruder, indicating greater chain entanglement. The change in the melt index can be at least 0.21, or 0.22, or 0.23, or 0.24, or 0.25, or 0.26 g / 10 min. When expressed as a percentage, this can be at least a 30% drop in the melt index, a 40% drop in the melt index, a 42% drop in the melt index, a 45% drop in the melt index, or a 48% drop in the melt index, and up to a 50%, 55%, or 60% drop in the melt index or more. The HLMI can also drop by a similar percentage. ARTICLES AND PRODUCTS

[0097] Articles of manufacture may be formed from and / or may comprise the olefin polymers (e.g., ethylene polymers) of this invention and, consequently, are covered in this document. For example, articles that may comprise the polymers of this invention may include, but are not limited to, an agricultural film, a geomembrane film, a packaging film, a wrapping film. Petition 870250088394, dated 09 / 30 / 2025, pp. 127 / 171 40 / 73 pallet, an automobile part, a bottle, a chemical container, a drum, a fiber or fabric, a food packaging film or container, a food service article, a fuel tank, a geomembrane, a household container, a liner, a molded product, a medical device or material, an outdoor storage product, outdoor recreational equipment, a tube, a sheet or tape, a toy or traffic barrier, and the like. Various processes can be employed to form these articles. Non-limiting examples of such processes include injection molding, blow molding, spin molding, film extrusion, sheet extrusion, profile extrusion, thermoforming, and the like. Additionally, additives and modifiers are frequently added to these polymers in order to provide beneficial polymer processing or end-use product attributes.Such processes and materials are described in Modern Plastics Encyclopedia, Mid-November 1995 Issue, Vol. 72, No. 12; and Film Extrusion Manual - Process, Materials, Properties, TAPPI Press, 1992. In some aspects of this invention, a manufactured article may comprise any of the olefin polymers (or ethylene polymers) described herein, and the manufactured article may be or may comprise a film (e.g., a blown film), a tube, or a blow-molded product. EXAMPLES

[0098] This invention is further illustrated by the following examples, which should not be interpreted as imposing limitations on the scope of the invention in any way. Various other aspects, modifications, and equivalents thereof, which, after reading the description in this document, may of themselves be suggested to one skilled in the art without departing from the spirit of the present invention or the scope of the appended claims.

[0099] The activation of standard catalyst for control or comparative catalysts in laboratory tests was carried out as follows. Approximately 10 g of a catalyst sample were placed Petition 870250088394, dated 09 / 30 / 2025, pp. 128 / 171 41 / 73 in a 1.75-inch quartz tube fitted with a sintered quartz disc at the bottom. While the catalyst was supported on the disc, dry air was blown through the disc at a linear rate of 1.6–1.8 standard ft³ / h (45–51 L / h). An electric furnace around the quartz tube was then switched on and the temperature was raised at a rate of 400 °C / h until the indicated temperature, typically 650 °C, was reached. At this temperature, the catalyst was fluidized for 3 h in dry air. Later, the catalyst was collected and stored under dry nitrogen, where the catalyst was protected from oxygen and moisture until ready for the polymerization test.

[0100] The catalysts of the invention used the same equipment in the laboratory, but the procedure was quite different. Typically, the catalyst was cycled between air and nitrogen at a low temperature and then the catalyst was heated to the maximum temperature in nitrogen. After a holding period, the temperature was lowered to another temperature where the gas stream was switched to air. After another holding period, the catalyst was cooled to 200-350 °C in air. The gas stream was changed back to nitrogen at this temperature and the catalyst was purged in nitrogen for a further 30 min. Then, the catalyst was cooled to room temperature in nitrogen and bottled for further testing. This general activation procedure of the invention was used, but specific temperatures and times were varied for different experiments.

[0101] Activation method A: The catalyst was treated as described in the standard activation procedure for control or comparative catalysts.

[0102] Activation Method B: The same procedure was used as in Activation A, except that the final temperature was 704 °C instead of 650 °C.

[0103] Activation Method C: The catalyst was charged in two increments under nitrogen. Three air cycles up to 350 °C, followed by cooling to 150 °C in nitrogen. Then, nitrogen up to 704 °C, maintain Petition 870250088394, dated 09 / 30 / 2025, pp. 129 / 171 42 / 73 for 4 hours. Cool to 550°C in nitrogen, then switch to air. Keep in air for 1 hour. Cool in air to 300°C, then purge with nitrogen for 30 minutes, cool and bottle.

[0104] Activation Method D: The same procedure was used as in Activation C, except that the retention period at 550 °C was 2 h instead of 1 h.

[0105] Other catalyst activations (EH Methods) were conducted in a large-scale fluidized bed calciner, with a diameter of 42 in, with gas flows of 0.1 ft / s below 700 °C and 0.2 ft / s above that temperature. The calciner had a similar design to the laboratory quartz activator, only built on a much larger scale. The quoted temperature (in the calciner) was the average of three (3) thermocouples positioned at the top, bottom, and middle of the fluidized bed calciner. The catalyst / pre-catalyst temperature is effectively the same as the calciner temperature.

[0106] Activation Method E: The catalyst, 600 lb, was charged as a single charge in nitrogen, then the atmosphere was changed to air. The temperature was raised at a ramp rate of 2.7 °F / min (1.5 °C / min) to 1350 °F (732 °C). The catalyst was held at this temperature for 8 h, then cooled in air to 600 °F (315 °C), where the catalyst was purged with nitrogen for 3 h, then discharged.

[0107] Activation Method F: Approximately 600 lb of catalyst were loaded into the calciner under nitrogen in four unequal portions while the temperature was at 600 °F (315 °C). The first portions were slightly smaller than the later ones. The temperature dropped rapidly to 450–500 °F (232–260 °C) with each portion being loaded, and then the temperature recovered back to 600 °F (315 °C). After all the catalyst was loaded, the atmosphere was changed to air, and the temperature began to rise as the volatile compounds in the catalyst were oxidized. When the temperature reached 900 °F (482 °C), the atmosphere was changed back. Petition 870250088394, dated 09 / 30 / 2025, pp. 130 / 171 43 / 73 to nitrogen and the temperature gradually dropped back to about 600 °F (315 °C). This cycle was repeated three times until there was no more exothermic reaction. Then, in nitrogen, the temperature was raised to 1300 °F (704 °C) at a ramp rate of 2.4 °F / min (1.3 °C / min) and held at that temperature for 5 h. While still in nitrogen, the temperature was then cooled to 1025 °F (552 °C). The atmosphere was again changed to air and the catalyst was held at that temperature for 5 h. The catalyst was then cooled in air to 650 °F (343 °C) and the atmosphere was again changed back to nitrogen. After purging for 3 h, the catalyst was discharged into a hermetically sealed metal tank.

[0108] Activation Method G: The Activation F procedure was followed, except that the catalyst was loaded in two equal portions and the air treatment at 1025 °F (552 °C) was 2 h. FIG. 1 is a representation of a time-temperature activation sequence similar to that of Activation Methods FG, and FIG. 2 further illustrates the exothermic elimination portion of FIG. 1.

[0109] Activation Method H: The catalyst was loaded as a single portion into air. The temperature was raised at 2.7 °F / min (1.5 °C / min) to 1200 °F (649 °C), where it was held for 8 h, then cooled in air to 600 °F (315 °C) where it was purged with nitrogen for 3 h, then discharged. FIG. 3 is a representation of a time-temperature activation sequence similar to that of Activation Method H.

[0110] Laboratory-activated and large-scale-activated catalysts were tested in polymerization experiments that were carried out as follows: In a 2.2 L steel reactor equipped with a marine agitator rotating at 500 rpm. The reactor was surrounded by a steel jacket through which a mixture of steam and water was passed, which was adjusted to maintain a constant temperature of 105 °C (+ / - 0.5 °C) with the aid of electronic control instruments. Unless otherwise defined, a small amount (0.01 to 0.10 g typically) of the solid catalyst was first Petition 870250088394, dated 09 / 30 / 2025, pp. 131 / 171 44 / 73 charged under nitrogen in the dry reactor. Then, 1.2 L of liquid isobutane was charged and the reactor heated to the specified temperature (105 °C). Finally, ethylene was added to the reactor to equalize a fixed pressure, 550 psig, which was maintained throughout the experiment. Stirring was continued until approximately 3000 grams of polymer were produced per gram of catalyst, and the instantaneous reaction rate was recorded by registering the ethylene flow in the reactor to maintain the set pressure.

[0111] After the desired productivity of 3000 g / g was reached, the ethylene flow was stopped and the reactor was slowly depressurized and opened to recover a granular polymer powder. In all cases, the reactor was clean, with no indication of any wall fouling, lining, or other forms of soot. The polymer powder was then removed and weighed. The activity was specified as g of polymer produced per g of solid catalyst loaded per h.

[0112] The melt index and high-load melt index were then obtained from the recovered polymer. Melt Index (MI, I2, g / 10 min) was determined according to ASTM D1238-E, Condition 190 / 2, at 190 °C with a weight of 2.16 kg. High-load melt index (HLMI, I21, g / 10 min) was determined according to ASTM D1238-F, Condition 190 / 21.6, at 190 °C with a weight of 21.6 kg. These two values, having been obtained from polymer made under standardized reactor conditions, were then used for comparison between the catalysts for their melt index potential (MIP) or high-load melt index potential (HLMIP). Density was determined in grams per cubic centimeter (g / cm3) in a compression-molded sample, cooled at 15 °C per minute and conditioned for 40 hours at room temperature according to ASTM D1505 and ASTM D4703.

[0113] Molecular weights and molecular weight distributions were obtained using a PL-GPC 220 system (Polymer Labs, an Agilent company) equipped with an IR4 detector (Polymer Char, Spain) and three GPC columns. Petition 870250088394, dated 09 / 30 / 2025, pp. 132 / 171 45 / 73 Styragel HMW-6E (Waters, MA) was run at 145 °C with a mobile phase flow rate of 1,2,4-trichlorobenzene (TCB) containing 0.5 g / L of 2,6-di-t-butyl-4-methylphenol (BHT) fixed at 1 mL / min, and polymer solution concentrations were in the range of 1.0–1.5 mg / mL, depending on molecular weight. Sample preparation was conducted at 150 °C for approximately 4 h with occasional gentle stirring before the solutions were transferred to sample vials for injection. An injection volume of approximately 400 μL was used. The integral calibration method was used to deduce molecular weights and molecular weight distributions using a Chevron Phillips Chemical Company HDPE polyethylene resin, MARLEX® BHB5003, as the broad standard. A comprehensive table of the broad standard was predetermined in a separate experiment with SEC-MALS.Mn is the number-average molecular weight, Mw is the weight-average molecular weight, Mz is the average molecular weight, and Mp is the maximum molecular weight (the location, in molecular weight, of the highest point on the molecular weight distribution curve).

[0114] The rheological characterizations of the melt were performed as follows. Small-strain (less than 10%) oscillatory shear measurements were performed on an Anton Paar MCR rheometer using parallel plate geometry. All rheological tests were performed at 190°C. The complex viscosity data |η*| versus frequency (ω) were then fitted to the curve using the modified three-parameter Carreau-Yasuda (CY) empirical model to obtain the zero shear viscosity - ηο, viscous relaxation time characteristics - τη and the width parameter - α (CY-a parameter). The simplified Carreau-Yasuda (CY) empirical model is shown below: η*(ω) ηο [1 + (τηω)a](1- n) / a, where: | η*(ω) | = magnitude of the complex shear viscosity; Petition 870250088394, dated 09 / 30 / 2025, pp. 133 / 171 46 / 73 ηο = zero shear viscosity; τη = viscous relaxation time (Tau(n)); a = width parameter (CY-a parameter); n = sets the final slope of the force law, fixed at 2 / 11; and ω = angular frequency of oscillatory shear deformation.

[0115] Details of the significance and interpretation of the CY model and derived parameters can be found in: CA Hieber and HH Chiang, Rheol. Acta, 28, 321 (1989); CA Hieber and HH Chiang, Polym. Eng. Sci., 32, 931 (1992); and RB Bird, RC Armstrong and O. Hasseger, Dynamics of Polymeric Liquids, Volume 1, Fluid Mechanics, 2nd Edition, John Wiley & Sons (1987).

[0116] Six (6) different precatalysts were made, each according to a slightly different procedure. It all started with about 550 lb of silica (dry basis) with a surface area of ​​450 m2 / g and a pore volume of 1.9 mL / g. The average d50 particle size was 60 microns. The silica was loaded into a 1,000 gal reactor and combined with 2,750 lb of deionized water. The fluid paste was stirred and other ingredients were added, as summarized in Table 1 below. After all ingredients were added, the mixture was spray-dried to form precatalysts 1-6. Precatalysts 1-6 nominally contained 1% by weight of chromium and 3.5% by weight of titanium, except for precatalyst 3, which contained 4% by weight of titanium.A commercially available comparative catalyst, designated as type M (1 wt% chromium and 2.5 wt% titanium), was also tested, and this catalyst had a surface area of ​​500 m² / g, a pore volume of 2.5 mL / g and an average particle size d50 of 130 microns. Petition 870250088394, dated 09 / 30 / 2025, pp. 134 / 171 47 / 73 Table 1 (quantities in lb) Pre-catalyst 1 2 3 4 5 6 Titanium tetraisopropoxide 114 114 130 114 0 114 Oxalic acid dihydrate 101 101 116 126 0 101 Dimethylformamide (DMF) 88 88 100 88 0 0 Chromium triacetate 24.2 24.2 19.4 19.4 0 0 Basic Chromium acetate 0 0 0 0 22.9 18.3 Dimethylethanolamine 0 0 0 0 0 17.4 Triethane titanate solution 0 0 0 0 127 0 blade at 80% by weight

[0117] The melt index potential for precatalysts 1-6 that were activated using Comparative Activation Methods AB and Activation Methods CD of the invention are summarized in Tables 2-4. Each value shown in these tables represents the average of several tests. The high-charge melt index potential (HLMIP) is listed in Table 2 and the melt index potential (MIP) is listed in Table 3. In summary, activations of the invention using CD methods generally produced higher melt index and HLMI polymers than the comparative activation methods, even those activated at a higher temperature. This is advantageous during commercial operations. Beneficially, as shown below, this elevated MI potential was also achieved without negatively affecting other polymer properties.

[0118] Similar to Tables 2-4, Table 5 summarizes the melt index potential for precatalysts 1-5 and comparative catalyst M using Comparative Activation Methods E and H and FG Activation Methods of the invention (large-scale fluidized bed calcination). As above, activations of the invention using CD methods generally produced higher melt index and HLMI polymers than the comparative activation methods, even those activated at a higher temperature. Petition 870250088394, dated 09 / 30 / 2025, pp. 135 / 171 48 / 73 Table 2 - Potential high-load melting index of activated catalysts Pre-catalyst activation Method 1 2 3 4 5 6 A 32.8 25.7 25.0 24.9 22.5 30.6 B 40.8 44.8 35.9 40.6 34.8 44.2 C 39.7 79.3 D 79.7 A 30.1 29.3 27.1 37.0 35.2 40.3 Table 3 - Melting index potential of activated catalysts Activation Pre-catalyst Method 1 2 3 4 5 6 A 0.42 0.27 0.32 0.29 0.22 0.45 B 0.55 0.61 0.53 0.53 0.39 0.53 C 0.51 0.99 D 0.96 A 0.43 Table 4 - Shear response (HLMI / MI) of polymers Activation Pre-catalyst Method 1 2 3 4 5 6 A 77.8 94.3 78.9 86.0 102.3 68.0 B 74.2 73.4 67.7 76.5 89.2 83.4 C 77.8 80.1 D 83.0 A 69.4 72.0 74.2 69.2 70.4 66.5 Petition 870250088394, dated 09 / 30 / 2025, pp. 136 / 171 49 / 73 Table 5 - Large-scale HLMI activations HLMI / MI Activation Method Pre-Catalyst MI E 1 0.41 30.6 74.6 F 1 0.74 60.6 81.9 E 3 0.50 38.4 76.8 G 4 0.98 75.5 77.0 G 4 1.16 96.0 82.8 E 5 0.39 32.2 82.6 HM 0.45 30.6 68.0

[0119] Catalysts activated by inventive methods F and G were then used in a large-scale 18,000-gallon closed-loop reactor using isobutane diluent to make a series of polymers with a density of about 0.938 g / cc and a melting index of about 0.2 g / 10 min. Table 6 below shows the reaction conditions.

[0120] The rheology and gel permeation chromatography results are summarized in Table 7 below. Unexpectedly, the polymers of the invention, those made using the catalyst activation procedure of the invention, had a lower molecular weight than the control polymers, as well as a narrower molecular weight distribution (Mw / Mn or Mz / Mw). The polymers of the invention had a smaller CY-a parameter, which is the width of the relaxation time distribution, and an HLMI that was much larger for the same melt index, despite having a lower molecular weight. In addition, the tan delta shear rate at 0.1 / sec was also lower. In short, this is a unique and beneficial combination of rheology and molecular weight characteristics.

[0121] These molecular weight and rheological features result in some processing advantages during pelletizing and extrusion / conversion operations. These polymers were then blown into 25 micron film and compared. The physical properties, dart drop resistance and Petition 870250088394, dated 09 / 30 / 2025, pp. 137 / 171 50 / 73 tear resistance MD and TD were identical within the margin of error. But the processing was quite different. Table 8 summarizes the extrusion and film blowing performance. Processability was improved with the polymers of the invention. Despite similar MI and density, the extruder amperage during film blowing was lower (requiring less energy). In Table 8, the average polymer of the invention consumed 17.3% less energy (current). Similarly, the extrusion pressure, measured at the extruder head, was lower, and likewise, the pressure on the screen was lower. The average polymer of the invention required 13.9% less head pressure and 15.2% less screen pressure than the average control polymer. Thus, the melting temperature was lower due to the improved extrusion processing capability. In the examples shown in Table 8, the average polymer of the invention had a melting temperature that was 6.8 °F (3.8 °C) lower than the average control polymer.These differences were observed even when the extruder rpm and output rate were the same.

[0122] The improved extrusion ease exhibited by the polymers of the invention was also evident in the pelletizing of the polymer during manufacturing. This is summarized in Table 9 below, which compares the pelletizing parameters between the polymers of the invention and the control. Although the pelletizing rate and the final melt index were not altered, the polymer of the invention extruded more easily than the control polymer. This is evident from the 9% lower pressure and the 4% lower specific energy, and also from the lower melting temperature of 24 °F (13 °C). This means that less work was put into the polymer during pelletizing, which thus produces a lower melting temperature, costing less and causing less mechanical and thermal degradation. However, there was a greater change in the melt index after pelletizing the polymer of the invention. This is shown in Table 9 by the absolute change in MI and also by the percentage change in MI.The decrease in the melting point through pelletizing is a result of mixing, that is, chain entanglement, which increases the viscosity. Petition 870250088394, dated 09 / 30 / 2025, pp. 138 / 171 51 / 73 melting point. Thus, the increased drop in the melting point can be taken as a sign of superior mixing in the polymer of the invention.

[0123] Another surprising aspect of these polymers of the invention was their extremely low film gel counts when formed into a 25-micron thick film. Gels larger than 200 microns in diameter were measured with an automatic camera on a 25-micron thick film formed from the polymers as they were made during the manufacturing process. Although the descriptive report is normally 170 gels / ft² or less, these polymers of the invention had gel counts well below that. The gel data are summarized in Table 8. Typical gel count values ​​during the production of this polymer grade (density of 0.938 g / cc and melt index of 0.2 g / 10 min) range from 60 to 120 gels / ft². However, as shown in Table 8, all polymers of the invention unexpectedly produced films with single-digit gel counts. During its production, individual hourly values ​​frequently dropped to 3 or even 2 gels / ft².While not wishing to be limited by the following theory, it is believed that the unexpectedly low gel count resulted from a combination of catalyst productivity, high catalyst activation / calcination temperature, and catalyst particle size distribution. Table 10 summarizes the gel count, catalyst productivity, and ppm data for ash, titanium, and chromium (ppm silica is the ash content minus the total chromium and titanium content). For the polymers of the invention, the chromium content was 3-4 ppm, the titanium content was 12-14 ppm, and the silica content was 330-370 ppm, and as noted above, the gel counts were less than 10 gels / ft².

[0124] In addition, further tests were carried out on another 2,025 samples of the polymers of the invention in Tables 6-10; the chromium content was in the range of 2.4-4.2 ppm, the titanium content was in the range of 8.5-14.8 ppm, the silica content was in the range of 233-403 ppm and the gel count was in the range of 3-17 gels / ft2 (and the average gel count was ~6 gels / ft2). Petition 870250088394, dated 09 / 30 / 2025, pp. 139 / 171 52 / 73

[0125] Gel counting was performed on 25 µm thick film from a Killion 125 cast film line with a die width of 203 mm. This used a CR7 winder model, using a cooler bath temperature of 23 °C. The gel inspection area was 3 square meters. The screw diameter was 1.24 inches, running at 10 rpm, the line speed at approximately 3 lb / h, and the temperature zones were all set to 400 °F. The upper and lower take-up rollers were set at 35. Before measurements were taken, the machine was purged for 120 minutes. The cooling roller speed was set to 23 rpm.

[0126] Film gels were measured on 25 µm thick film using a camera-based automated gel counting machine; the camera model was an FSA100 software and an optical control system (OCS) was used. The system included a light source and a detector. The film was passed through the system, between the light source and the detector, with an inspection width of 150 mm. The 3 square meters of film area were inspected and gels with sizes (diameters) greater than 200 µm were analyzed and then normalized per square foot of film – this is the gels / ft² measured from the 25 micron thick film in Table 8.

[0127] As noted above, catalyst particles of 100+ µm in diameter generally register as gels of 200+ µm, due to the polymer sometimes clinging to the catalyst particle, thus adding to its size, and also because of the lens effect, in which the catalyst particle appears magnified by the lens-shaped polymer coating. The latter is an optical magnification of the catalyst particle size due to the formation of a convex lens made of transparent polymer surrounding the catalyst particle. Thus, catalyst particle gels can be reduced by minimizing catalyst particles of 100 µm or more in size in the ethylene polymer.

[0128] To determine the quantity of all gels that were catalyst particle gels, the composition of each of the gels can be Petition 870250088394, dated 09 / 30 / 2025, pp. 140 / 171 53 / 73 determined (e.g., catalyst particles, cellulose, crosslinked polymer, additives, and so on). A skilled craftsman would readily be able to determine the cause of the gels using a variety of non-limiting techniques, such as hot-stage microscopy (and observing melting behavior), infrared spectroscopy, electron microscopy, and the like. For example, an IR spectrum can be used to help determine whether the gel is the result of a catalyst particle or something else. IR can even be used to determine which catalyst is responsible for the gels, in situations where multiple catalysts are used in a reactor to make different grades of polymer.

[0129] The ash content of the polymer can be determined by the ASTM D5630-13 B procedure. In this document, the ASTM ash content includes the amount of solid oxide (e.g., silica), chromium, and titanium. Because chromium and titanium are typically a much smaller portion of the ash content, the ash content is very close to the solid oxide (e.g., silica) content, but the solid oxide (e.g., silica) content in this document is equal to the ash content minus the total chromium and titanium content.

[0130] Most Cr polymerization catalysts nominally contain about 1% by weight of total Cr, usually in the form of Cr(III) before calcination. During this last preparation step, the catalyst is then activated by calcination, which converts a portion of the initial Cr(III) to Cr(VI). The activation process disclosed in this document converts most of the Cr to Cr(VI). The chromium(VI) content of the calcined or ash catalyst can be determined as follows. A small sample, typically about half a gram, is first suspended in about 25 mL of deionized water and 25 mL of 18 N sulfuric acid, to which 4 drops of indicator solution (1,10-phenanthroline iron(II) sulfate, 0.025 M in water) are added, all in a 250 mL beaker with a magnetic stirring bar. The resulting mixture is usually a yellow-green color. While stirring, this mixture is titrated using approximately 0.025 M ammonium sulfate solution. Petition 870250088394, dated 09 / 30 / 2025, pages 141 / 171 54 / 73 ferrous (FAS). The mixture should undergo several color changes, becoming more green and gradually turning blue, then rapidly becoming reddish-orange. When the mixture becomes reddish-orange, the titration is complete. The % by weight of Cr(VI) is determined from the following formula: % by weight of chromium = 1.733% (molarity FAS)(FAS mL) / (sample in g). Table 6 Catalyst of the Invention Control Rate, klb / h 48.8 51.2 Temp °F 193.3 193.3 Temp °C 90 90 Catalyst Injection Rate 12.4 12.3 C6= / C2=, lb / klb 61.2 55.5 Solids 41.5% 41.7% C2=concentration 3.69% by weight% 4.05% by weight% H2 Concentration 0.65% by mol 0.63% by mol Residence Time Rxn 44 min 42 min Petition 870250088394, dated 09 / 30 / 2025, pp. 142 / 171 55 / 73 Table 7 Sample η0 Pa-s Tau s CY-a of the Invention 8.09E+05 2.52 0.1508 of the Invention 1.05E+06 3.38 0.1485 of the Invention 1.10E+06 3.49 0.1482 of the Invention 1.29E+06 4.14 0.1455 of the Invention 1.39E+06 4.41 0.1443 Control 3.43E+05 1.01 0.1833 Control 3.76E+05 1.16 0.1829 Control 1.37E+06 5.10 0.1579 Control 6.53E+05 2.07 0.1741 MI dg / min HLMI dg / min Tan δ 0.1 / s Mn kg / mol Mw kg / mol Mz kg / mol Mw / Mn Mz / Mw 0.42 29.2 1.539 12.7 154.4 947 12.2 6.1 0.36 26.0 1.491 13.4 154.7 855 11.6 5.5 0.35 24.9 1.485 13.0 169.1 1338 13.0 7.9 0.34 24.8 1.457 13.3 157.1 1004 11.8 6.4 0.33 24.1 1.447 12.8 161.3 1055 12.6 6.5 0.32 18.4 1.791 14.6 190.8 1424 13.1 7.5 0.30 17.9 1.755 15.7 198.5 1586 12.6 8.0 0.21 15.2 1.435 10.1 185.0 1580 18.4 8.5 0.23 14.1 1.613 12.3 190.0 1499 15.5 7.9 Petition 870250088394, dated 09 / 30 / 2025, pp. 143 / 171 56 / 73 Table 8 Nominal Example: Density MI Current Pressure g / mL dg / min amp psig of the Invention 0.9387 0.24 20 3076 of the Invention 0.9387 0.26 28 3024 of the Invention 0.9384 0.27 22 2889 of the Invention 0.9386 0.25 27 3096 Control 0.9390 0.18 23 3505 Control 0.9390 0.19 32 3542 Control 0.9387 0.22 33 3485 Fusion Sieve Gels Temperature °F Extruder RPM Specific Rate ft / min at 1 mil Pressure psig >200 µm gels / sq ft 438 41 6.10 164 1925 5 437 41 170 1840 3 437 41 165 1845 6 438 41 167 1906 3 442 42 5.95 160 2202 60-120 446 42 5.95 165 2335 60-120 445 41 166 2109 60-120 to the Petition 870250088394, dated 09 / 30 / 2025, pages 144 / 171 57 / 73 Table 9 Polymer Control of the Invention Extruder Rate, klbs / h 48.7 48.4 Melting Temp., °F 425 449 Melting Temp., °C 218 232 Specific Energy, Wh / lb 76.0 79.2 Pressure, psig* 2183 2399 Pellet Melting Index 0.261 0.265 Initial Powder MI** 0.538 0.466 MI Change 0.277 0.202 % MI Change 51% 43% * in the sieve pack ** melting point of the initial polymer powder exiting the reactor Table 10 Example E Gel Count Productivity (lb / lb) Ash (ppm) Cr (ppm) Ti (ppm) of the Invention (5 / ft²) 2611 383 3.8 13.4 of the Invention (3 / ft²) 2841 352 3.5 12.3 of the Invention (6 / ft²) 2874 348 3.5 12.2 of the Invention (3 / ft²) 2817 355 3.6 12.4 Control (60-120 / ft²) 2959 338 3.4 8.5 Control (60-120 / ft²) 3356 298 3.0 7.5 Control (60-120 / ft²) 3030 330 3.3 8.3

[0131] The invention is described above with reference to numerous specific aspects and examples. Many variations will be suggested to those skilled in the art in light of the detailed description above. All such obvious variations are within the intended scope of the appended claims. Other aspects of the invention may include, but are not limited to, the following (the aspects are described as comprising, but alternatively may consist of Petition 870250088394, dated 09 / 30 / 2025, pages 145 / 171 58 / 73 essentially in or consist of):

[0132] Aspect 1. A process for producing an activated (calcined) chromium catalyst comprising (i) placing a precatalyst in contact with a first inert atmosphere at a temperature T1 in a range of 500 °F to 700 °F (260 °C to 371 °C), wherein the precatalyst comprises a silica support and 0.1 to 5% by weight of chromium, 0.1 to 10% by weight of titanium and 1 to 5 mol of nitrogen / mol of titanium;(ii) subjecting the precatalyst to cycles of a first oxidizing atmosphere at a temperature T2 in a range of 500 °F to 700 °F (260 °C to 371 °C) and a second inert atmosphere at a temperature T3 in a range of 700 °F to 900 °F (371 °C to 482 °C), wherein the first oxidizing atmosphere causes an exothermic temperature increase from T2 to T3, thus triggering the introduction of the second inert atmosphere which results in cooling to T2, until the exothermic temperature increase in the first oxidizing atmosphere is less than or equal to 50 °F (28 °C) within 15 min or when heat must be added to maintain T3 in the presence of the first oxidizing atmosphere; (iii) heat the precatalyst in a third inert atmosphere to a temperature T4 in a range of 1000 °F to 1400 °F (538 °C to 760 °C) and hold the precatalyst at T4 in the third inert atmosphere for a retention time t1 in a range of 1 h to 15 h;(iv) cool the precatalyst in a fourth inert atmosphere at a temperature T5 in a range of 900 °F to 1200 °F (482 °C to 649 °C), where T5 is lower than T4; (v) subject the precatalyst to a second oxidizing atmosphere at T5 for a retention time t2 in a range of 30 min to 10 h; (vi) cool in a third oxidizing atmosphere to a temperature T6 in a range of 500 °F to 700 °F (260 °C to 371 °C) to produce the activated (calcined) chromium catalyst; and (vii) purge the activated (calcined) chromium catalyst in a fifth inert atmosphere at T6 and cool to room temperature.

[0133] Aspect 2. The process, defined in aspect 1, in which in step (vii), the activated (calcined) chromium catalyst is purged with the fifth Petition 870250088394, dated 09 / 30 / 2025, pp. 146 / 171 59 / 73 inert atmosphere at T6 for a purge time t3 in any suitable range or any range disclosed in this document, for example, from 2 min to 20 h, from 5 min to 12 h, from 5 min to 5 h, from 15 min to 4 h or from 30 min to 6 h.

[0134] Aspect 3. The process, defined in any of the aspects above, additionally comprising before step (i), a step of charging and heating the pre-catalyst in the first inert atmosphere up to T1.

[0135] Aspect 4. The process, defined in aspect 3, in which the precatalyst is at a temperature from ambient to 120 °F (49 °C) before loading.

[0136] Aspect 5. The process, defined in aspect 3 or 4, in which loading the precatalyst in the contact step (i) occurs in 2-10 portions of a total quantity of precatalyst.

[0137] Aspect 6. The process, defined in aspect 5, in which during the loading of each portion of the total quantity of precatalyst, the temperature is maintained in a temperature range of 300 to 600 °F (149 °C to 315 °C) or 400 to 600 °F (204 °C to 315 °C).

[0138] Aspect 7. The process, defined in aspect 5 or 6, in which the loading of each portion of the total amount of precatalyst is stopped when the temperature falls below 400 °F (204 °C), or below 300 °F (149 °C).

[0139] Aspect 8. The process, defined in any of aspects 5-7, in which the loading of each portion of the total amount of precatalyst is stopped when the pressure increases above 1 psig.

[0140] Aspect 9. The process, defined in any of the preceding aspects, in which the first inert atmosphere, the third inert atmosphere, the fourth inert atmosphere, the fifth inert atmosphere and the sixth inert atmosphere are the same or different and independently comprise (or consist essentially of, or consist of) nitrogen, argon or a combination thereof. Petition 870250088394, dated 09 / 30 / 2025, pp. 147 / 171 60 / 73

[0141] Aspect 10. The process, defined in any of aspects 1-9, in which the third inert atmosphere and the fourth inert atmosphere are the same.

[0142] Aspect 11. The process, defined in any of aspects 1-9, in which the third inert atmosphere and the fourth inert atmosphere are different.

[0143] Aspect 12. The process, defined in any of the preceding aspects, in which the second inert atmosphere in each cycle of step (ii) is the same or different and independently comprises (or essentially consists of, or consists of) nitrogen, argon or a combination thereof.

[0144] Aspect 13. The process, defined in any of the preceding aspects, in which the second oxidizing atmosphere and the third oxidizing atmosphere independently comprise (or consist essentially of, or consist of) oxygen, air, a mixture of oxygen and an inert gas (for example, nitrogen), a mixture of air and an inert gas (for example, nitrogen) or a combination thereof, with any suitable % by volume of oxygen, for example, from 1 to 100% by volume, from 1 to 50% by volume, from 2 to 30% by volume, from 3 to 25% by volume or from 4 to 21% by volume.

[0145] Aspect 14. The process, defined in any of aspects 1-13, in which the second oxidizing atmosphere and the third oxidizing atmosphere are the same.

[0146] Aspect 15. The process, defined in any of aspects 1-13, in which the second oxidizing atmosphere and the third oxidizing atmosphere are different.

[0147] Aspect 16. The process, defined in any of the preceding aspects, in which the first oxidizing atmosphere in each cycle of step (ii) is the same or different and independently comprises (or essentially consists of, or consists of) oxygen, air, a mixture of oxygen and a Petition 870250088394, dated 09 / 30 / 2025, pp. 148 / 171 61 / 73 inert gas (e.g., nitrogen), a mixture of air and an inert gas (e.g., nitrogen) or a combination thereof, with any suitable % by volume of oxygen, for example, from 1 to 100% by volume, from 1 to 50% by volume, from 2 to 30% by volume, from 3 to 25% by volume or from 4 to 21% by volume.

[0148] Aspect 17. The process, defined in any of the preceding aspects, wherein T1 is in any suitable range or in any range disclosed in this document, for example, 550 °F to 650 °F (288 °C to 343 °C), 600 °F to 700 °F (315 °C to 371 °C) or 600 °F to 650 °F (315 °C to 343 °C).

[0149] Aspect 18. The process, defined in any of the preceding aspects, wherein T2 is in any suitable range or in any range disclosed in this document, for example, 600 °F to 700 °F (315 °C to 371 °C), 500 °F to 650 °F (260 °C to 343 °C), 625 °F to 700 °F (329 °C to 371 °C) or 575 °F to 675 °F (302 °C to 357 °C).

[0150] Aspect 19. The process, defined in any of the preceding aspects, wherein T3 is in any suitable range or in any range disclosed in this document, for example, 700 °F to 850 °F (371 °C to 454 °C), 700 °F to 800 °F (371 °C to 427 °C), 725 °F to 900 °F (385 °C to 482 °C) or 750 °F to 850 °F (399 °C to 454 °C).

[0151] Aspect 20. The process, defined in any of the preceding aspects, in which step (ii) is carried out until the exothermic temperature rise in the first oxidizing atmosphere is less than or equal to 40 °F (22 °C), less than or equal to 25 °F (14 °C), or less than or equal to 10 °F (6 °C), within 15 min.

[0152] Aspect 21. The process, defined in any of the aspects above, wherein step (ii) comprises any suitable number of cycles or any number of cycles disclosed in this document, for example, 2 to 10, 2 to 6, 2 to 4, 2 to 3, 3 to 8, 3 to 5, 4 to 10 or 4 to 6. Petition 870250088394, dated 09 / 30 / 2025, pp. 149 / 171 62 / 73

[0153] Aspect 22. The process, defined in any of the aspects above, in which any suitable heating rate is used in step (iii) or any heating rate disclosed in this document, for example, 1 to 5 °F / min (0.6 to 3 °C / min), 1.5 to 4 °F / min (0.8 to 2.2 °C / min) or 2 to 3.5 °F / min (1 to 2 °C / min).

[0154] Aspect 23. The process, defined in any of the preceding aspects, wherein T4 is in any suitable range or in any range disclosed in this document, for example, from 1000 °F to 1300 °F (538 °C to 704 °C), from 1100 °F to 1400 °F (593 °C to 760 °C), from 1100 °F to 1300 °F (593 °C to 704 °C) or from 1200 °F to 1300 °F (649 °C to 704 °C).

[0155] Aspect 24. The process, defined in any of the aspects above, where t1 is in any suitable range or in any range disclosed in this document, for example, 1 ha 8 h, 2 ha 10 h, 3 ha 15 h, 3 ha 8 h or 4 ha 6 h.

[0156] Aspect 25. The process, defined in any of the preceding aspects, in which any suitable cooling rate is used in step (iv) or any cooling rate disclosed in this document, for example, 1 to 4 °F / min (0.6 to 2.2 °C / min), 1.5 to 3.5 °F / min (0.8 to 2 °C / min) or 2 to 3 °F / min (1 to 1.7 °C / min).

[0157] Aspect 26. The process, defined in any of the preceding aspects, wherein T5 is in any suitable range or in any range disclosed in this document, for example, from 900 °F to 1100 °F (482 °C to 593 °C), from 950 °F to 1150 °F (510 °C to 621 °C), from 1000 °F to 1200 °F (538 °C to 649 °C) or from 1000 °F to 1100 °F (538 °C to 593 °C).

[0158] Aspect 27. The process, defined in any of the aspects above, where t2 is in any suitable range or in any range disclosed in this document, for example, from 30 min to 8 h, from 1 ha to 10 h, from 1 ha to 8 h, from 2 ha to 6 h or from 3 ha to 5 h.

[0159] Aspect 28. The process, defined in any of the aspects above, where t2 is a period of time sufficient to form Petition 870250088394, dated 09 / 30 / 2025, pp. 150 / 171 63 / 73 at least 30% by weight, at least 50% by weight, at least 70% by weight, or at least 80% by weight of chromium (VI), based on the amount of chromium in the activated (calcined) chromium catalyst.

[0160] Aspect 29. The process, defined in any of the preceding aspects, wherein T6 is in any suitable range or in any range disclosed in this document, for example, 500 °F to 650 °F (260 °C to 343 °C), 550 °F to 700 °F (288 °C to 371 °C), 550 °F to 650 °F (288 °C to 343 °C) or 600 °F to 675 °F (315 °C to 357 °C).

[0161] Aspect 30. The process, defined in any of the aspects above, where T6 is within 50 °F (28 °C), within 25 °F (14 °C) or within 10 °F (6 °C) of T1.

[0162] Aspect 31. The process, defined in any of the preceding aspects, in which any suitable cooling rate is used in step (vi) or any cooling rate disclosed in this document, for example, 1 to 4 °F / min (0.6 to 2.2 °C / min), 1.5 to 3.5 °F / min (0.8 to 2 °C / min) or 2 to 3 °F / min (1 to 1.7 °C / min).

[0163] Aspect 32. The process, defined in any of the preceding aspects, in which the activated (calcined) catalyst has a higher melt index potential (by any suitable amount or any amount disclosed in this document, for example, at least 10% higher, at least 25% higher, at least 50% higher, at least 75% higher or at least 100% higher) than that of an otherwise identical catalyst (or control catalyst) activated by exposure to an oxidizing atmosphere at a temperature of 1200 °F (649 °C) for a period of 3 h (or 8 h), when measured by means of MI, HLMI or both.

[0164] Aspect 33. The process, defined in any of the preceding aspects, in which the activated (calcined) catalyst produces a polymer under standard polymerization conditions with an Mw / Mn ratio (or Mz / Mw, or CY-a parameter) that is within 35% (or within 30%, 25%, 20%, 15%, 10% or 5%) of the Mw / Mn (or Mz / Mw, or CY-a parameter) of a Petition 870250088394, dated 09 / 30 / 2025, pages 151 / 171 64 / 73 polymer produced using an otherwise identical catalyst (or control catalyst) activated by exposure to an oxidizing atmosphere at a temperature of 1200 °F (649 °C) for a period of 3 h (or 8 h).

[0165] Aspect 34. The process, defined in any of the preceding aspects, in which the activated (calcined) catalyst has an MI potential of at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, at least 0.9, at least 1 or at least 1.2 g / 10 min.

[0166] Aspect 35. The process, defined in any of the preceding aspects, in which the activated (calcined) catalyst has an HLMI potential of at least 20, at least 25, at least 30, at least 35, at least 40, at least 50, at least 60, at least 70, at least 80 or at least 100 g / 10 min.

[0167] Aspect 36. The process, defined in any of the preceding aspects, wherein the activated (calcined) catalyst produces a polymer under standard polymerization conditions that has a total film gel count (or a catalyst particle gel count) less than or equal to 100 gels per ft2 of 25 micron thick film (or less than or equal to 80, or less than or equal to 60, or less than or equal to 40, or less than or equal to 30, or less than or equal to 20, or less than or equal to 10, or less than or equal to 8, or less than or equal to 5 gels per ft2 of 25 micron thick film), wherein the film gels encompass a size (diameter) greater than 200 µm (and caused by catalyst particles for the catalyst particle gel count).

[0168] Aspect 37. The process, defined in any of the preceding aspects, in which the pre-catalyst (or the activated catalyst) is brought into contact with a gas stream at any suitable linear velocity or any linear velocity disclosed in this document, for example, 0.05 to 0.6 ft / s, 0.05 to 0.3 ft / s, 0.1 to 0.4 ft / s, 0.2 to 0.5 ft / s, 0.2 to 0.4 ft / s or 0.2 to 0.3 ft / s, in a fluidized bed vessel. Petition 870250088394, dated 09 / 30 / 2025, pp. 152 / 171 65 / 73 (in batch or continuous).

[0169] Aspect 38. An olefin polymerization process comprising (I) carrying out the process to produce the activated (calcined) chromium catalyst defined in any of aspects 1-37; and (II) bringing the activated (calcined) chromium catalyst and an optional cocatalyst into contact with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

[0170] Aspect 39. The olefin polymerization process, defined in aspect 38, in which a cocatalyst is used and the cocatalyst comprises any suitable cocatalyst or any cocatalyst disclosed in this document, for example, an aluminoxane cocatalyst, an organoaluminum cocatalyst, an organoboron cocatalyst or any combination thereof.

[0171] Aspect 40. The olefin polymerization process, defined in aspect 38 or 39, wherein the olefin monomer and the optional olefin comonomer independently comprise a C2-C20 alpha-olefin.

[0172] Aspect 41. The olefin polymerization process, defined in either of aspects 38-40, wherein the olefin monomer comprises ethylene.

[0173] Aspect 42. The olefin polymerization process, defined in either of aspects 38-41, in which the activated chromium catalyst is brought into contact with ethylene and an olefin comonomer comprising a C3-C10 alpha-olefin.

[0174] Aspect 43. The olefin polymerization process, defined in any one of aspects 38-42, in which the activated chromium catalyst is brought into contact with ethylene and an olefin comonomer comprising 1-butene, 1-hexene, 1-octene or a mixture thereof.

[0175] Aspect 44. The olefin polymerization process, defined in any of aspects 38-43, in which the reactor system of Petition 870250088394, dated 09 / 30 / 2025, pp. 153 / 171 66 / 73 polymerization comprises a fluid paste reactor, a gas phase reactor, a solution reactor or a combination thereof.

[0176] Aspect 45. The olefin polymerization process, defined in either of aspects 38-44, wherein the polymerization reactor system comprises a closed-circuit fluidized paste reactor.

[0177] Aspect 46. The olefin polymerization process, defined in any one of aspects 38-45, wherein the polymerization reactor system comprises a single reactor.

[0178] Aspect 47. The olefin polymerization process, defined in any of aspects 38-45, wherein the polymerization reactor system comprises 2 reactors.

[0179] Aspect 48. The olefin polymerization process, defined in any one of aspects 38-45, wherein the polymerization reactor system comprises more than 2 reactors.

[0180] Aspect 49. The olefin polymerization process, defined in any of aspects 38-48, wherein the olefin polymer comprises any olefin polymer disclosed in this document.

[0181] Aspect 50. The olefin polymerization process, defined in any one of aspects 38-49, wherein the olefin polymer comprises an ethylene homopolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer and / or an ethylene / 1-octene copolymer.

[0182] Aspect 51. The olefin polymerization process, defined in any one of aspects 38-50, wherein the polymerization conditions comprise a polymerization reaction temperature in a range of 60 °C to 120 °C and a reaction pressure in a range of 200 to 1000 psig (1.4 to 6.9 MPa).

[0183] Aspect 52. The polymerization process of olefins, defined in any of aspects 38-51, wherein the polymerization conditions are substantially constant, for example, for a particular grade of polymer. Petition 870250088394, dated 09 / 30 / 2025, pp. 154 / 171 67 / 73

[0184] Aspect 53. The olefin polymerization process, defined in any of aspects 38-52, in which no hydrogen is added to the polymerization reactor system.

[0185] Aspect 54. The olefin polymerization process, defined in either of aspects 38-52, in which hydrogen is added to the polymerization reactor system.

[0186] Aspect 55. The olefin polymerization process, defined in any of aspects 38-54, wherein the process is carried out at a productivity of 2000 to 5000 g of polymer per gram of catalyst and / or at a space-time yield greater than or equal to 2, 2.5, 2.8, 3 or 4 (lb / h) / gal and / or less than or equal to 6, 5.5 or 5 (lb / h) / gal, in a commercial closed-loop reactor producing at least one ethylene / hexene copolymer of density 0.947 g / cc, as determined by ISO 1183 part 2.

[0187] Aspect 56. The olefin polymerization process, defined in any of aspects 38-55, wherein the process is carried out at a productivity of 2000 to 5000 g of polymer per gram of catalyst and / or at a space-time yield greater than or equal to 2, 2.5, 2.8, 3 or 4 (lb / h) / gal and / or less than or equal to 6, 5.5 or 5 (lb / h) / gal, in a commercial closed-loop reactor producing at least one ethylene / hexene copolymer with a density of 0.938 g / cc, as determined by ISO 1183 part 2.

[0188] Aspect 57. The process, defined in any of the preceding aspects, in which the pre-catalyst (or silica support, or activated chromium catalyst) has any suitable (total) pore volume or a (total) pore volume in any range disclosed in this document, for example, 0.5 to 5 mL / g, 1 to 5 mL / g, 1 to 3 mL / g or 1.5 to 2 mL / g.

[0189] Aspect 58. The process, defined in any of the preceding aspects, in which the pre-catalyst (or silica support or activated chromium catalyst) has any suitable BET surface area or Petition 870250088394, dated 09 / 30 / 2025, pp. 155 / 171 68 / 73 a BET surface area in any range disclosed in this document, for example, from 100 to 700 m2 / g, from 200 to 600 m2 / g, from 250 to 550 m2 / g or from 300 to 500 m2 / g.

[0190] Aspect 59. The process, defined in any of the preceding aspects, in which the pre-catalyst (or silica support or activated chromium catalyst) has any suitable average particle size (d50) or an average particle size (d50) in any range disclosed in this document, for example, 10 to 500 microns, 30 to 130 microns or 40 to 70 microns.

[0191] Aspect 60. The process, defined in any of the preceding aspects, in which the pre-catalyst (or the activated chromium catalyst) has any suitable amount of titanium or an amount in any range disclosed in this document, for example, from 0.5 to 10% by weight, from 1 to 10% by weight, from 2 to 8% by weight or from 2 to 6% by weight of titanium, based on the weight of the respective catalyst.

[0192] Aspect 61. The process, defined in any of the preceding aspects, in which the pre-catalyst (or the activated chromium catalyst) has any suitable amount of chromium or an amount in any range disclosed in this document, for example, from 0.1 to 4% by weight, from 0.2 to 5% by weight, from 0.5 to 3% by weight, from 0.5 to 2% by weight or from 0.5 to 1.5% by weight of chromium, based on the weight of the respective catalyst.

[0193] Aspect 62. The process, defined in any of the preceding aspects, in which the pre-catalyst (or the activated chromium catalyst) has any suitable amount of nitrogen or an amount in any range disclosed in this document, for example, 1 to 4.5, 1.5 to 5, 1.5 to 4.5, 2 to 5, 2 to 4 or 2 to 3 mol of nitrogen / mol of titanium.

[0194] Aspect 63. The process, defined in any of the preceding aspects, in which the precatalyst has any suitable amount of a carboxylate group / ligand or an amount in any range disclosed in this document, for example, from 1 to 5, from 1 to 4, from 1 to 3, of Petition 870250088394, dated 09 / 30 / 2025, pp. 156 / 171 69 / 73 1.5 to 5, 1.5 to 4, or 2 to 3 moles of carboxylate / mol of titanium.

[0195] Aspect 64. The process, defined in any of the preceding aspects, in which the pre-catalyst has any suitable amount of carbon or an amount in any range disclosed in this document, for example, from 0.5 to 10% by weight, from 1 to 10% by weight, from 1 to 5% by weight, from 2 to 10% by weight, from 2 to 8% by weight or from 2 to 6% by weight of carbon, based on the weight of the catalyst.

[0196] Aspect 65. The process, defined in any of the preceding aspects, in which the amount of chromium in the precatalyst in an oxidation state of +5 or less is at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, or at least 95% by weight, based on the total amount of chromium in the precatalyst.

[0197] Aspect 66. The process, defined in any of the preceding aspects, in which the amount of chromium in the activated chromium catalyst in a hexavalent oxidation state is at least 40% by weight, at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, or at least 95% by weight, based on the total amount of chromium in the activated chromium catalyst.

[0198] Aspect 67. An olefin polymer (for example, an ethylene polymer) produced by the olefin polymerization process, defined in any of aspects 38-66.

[0199] Aspect 68. An ethylene polymer with (or characterized by) a high-charge melt index (HLMI) in a range of 10 to 80 g / 10 min; a density in a range of 0.93 to 0.96 g / cm3; and a total film gel count (or a catalyst particle gel count) of less than or equal to 100 gels per ft2 of 25 micron thick film (or less than or equal to 80, or less than or equal to 60, or less than or equal to 40, or less than or equal to 30, or less than or equal to 20, or less than or equal to 10, or less than or equal to 8, or less than Petition 870250088394, dated 09 / 30 / 2025, pp. 157 / 171 70 / 73 which is equal to or greater than 5, gels per ft² of 25 micron thick film), wherein the film gels span a size (diameter) greater than 200 μm (and caused by catalyst particles for catalyst particle gel count); wherein the ethylene polymer contains 150 to 680 ppm of silica, 1.5 to 6.8 ppm of chromium and 1.5 to 40 ppm of titanium.

[0200] Aspect 69. An ethylene polymer with (or characterized by) a melt index (MI) in the range of 0.1 g / 10 min to 1 g / 10 min; a density in the range of 0.93 to 0.96 g / cm3; and a total film gel count (or a catalyst particle gel count) less than or equal to 100 gels per ft² of 25 micron thick film (or less than or equal to 80, or less than or equal to 60, or less than or equal to 40, or less than or equal to 30, or less than or equal to 20, or less than or equal to 10, or less than or equal to 8, or less than or equal to 5 gels per ft² of 25 micron thick film), wherein the film gels encompass a size (diameter) greater than 200 μm (and caused by catalyst particles for the catalyst particle gel count); wherein the ethylene polymer contains 150 to 680 ppm of silica, 1.5 to 6.8 ppm of chromium, and 1.5 to 40 ppm of titanium.

[0201] Aspect 70. The polymer, defined in any of aspects 67-69, wherein the ethylene polymer has an HLMI in any range disclosed in this document, for example, 10 to 70, 10 to 60, 10 to 50, 20 to 80, 20 to 50 or 30 to 50 g / 10 min.

[0202] Aspect 71. The polymer, defined in any of aspects 67-70, wherein the ethylene polymer has an MI in any range disclosed in this document, for example, 0.1 to 1, 0.1 to 0.75, 0.1 to 0.6, 0.2 to 1, 0.2 to 0.6 or 0.3 to 0.6 g / 10 min.

[0203] Aspect 72. The polymer, defined in any of aspects 67-71, wherein the ethylene polymer has a density in any range disclosed in this document, for example, from 0.93 to 0.956, from 0.934 to 0.96, from 0.934 to 0.956, from 0.934 to 0.95 or from 0.945 to 0.958 g / cm3. Petition 870250088394, dated 09 / 30 / 2025, pp. 158 / 171 71 / 73

[0204] Aspect 73. The polymer, defined in any of aspects 67-72, in which the ethylene polymer independently contains less than 0.1 ppm (by weight), less than 0.08 ppm, less than 0.05 ppm or less than 0.03 ppm of Mg, V, Zr or Hf.

[0205] Aspect 74. The polymer, defined in any of aspects 67-73, wherein the ethylene polymer contains 1.8 to 6 ppm, 2 to 6.8 ppm, 2 to 6 ppm, 2 to 5 ppm, 2 to 4.5 ppm, 2 to 4 ppm, 1.5 to 6 ppm, 1.5 to 5.5 ppm, 1.5 to 5 ppm or 3 to 6 ppm of chromium.

[0206] Aspect 75. The polymer, defined in any of aspects 67-74, wherein the ethylene polymer contains from 1.5 to 30 ppm, from 2 to 40 ppm, from 2 to 30 ppm, from 2 to 10 ppm, from 3 to 30 ppm, from 3 to 20 ppm, from 3 to 10 ppm, from 4 to 20 ppm, from 5 to 40 ppm, from 5 to 25 ppm, from 5 to 15 ppm, from 7 to 17 ppm or from 8 to 16 ppm of titanium.

[0207] Aspect 76. The polymer, defined in any of aspects 67-75, wherein the ethylene polymer contains from 180 to 600 ppm, from 200 to 680 ppm, from 200 to 600 ppm, from 200 to 500 ppm, from 200 to 400 ppm, from 150 to 600 ppm, from 150 to 500 ppm or from 150 to 450 ppm of silica.

[0208] Aspect 77. The polymer, defined in any of aspects 67-76, wherein the ethylene polymer has a Mn in any range disclosed in this document, for example, from 3,000 to 25,000, from 8,000 to 20,000, from 10,000 to 18,000 or from 12,000 to 15,000 g / mol.

[0209] Aspect 78. The polymer, defined in any of aspects 67-76, wherein the ethylene polymer has an Mw in any range disclosed in this document, for example, from 100,000 to 250,000, from 120,000 to 200,000 or from 140,000 to 180,000 g / mol.

[0210] Aspect 79. The polymer, defined in any of aspects 67-78, wherein the ethylene polymer has an Mz in any range disclosed in this document, for example, from 500,000 to 2,000,000, from 500,000 to 1,800,000 or from 600,000 to 1,500,000 g / mol.

[0211] Aspect 80. The polymer, defined in any of the Petition 870250088394, dated 09 / 30 / 2025, pp. 159 / 171 72 / 73 aspects 67-79, where the ethylene polymer has an Mw / Mn ratio in any range disclosed in this document, for example, from 7 to 20, from 8 to 18, from 9 to 17, from 9 to 15 or from 10 to 14.

[0212] Aspect 81. The polymer, defined in any of aspects 67-80, wherein the ethylene polymer has an Mz / Mw ratio in any range disclosed in this document, for example, 5 to 10, 5 to 9, 6 to 10 or 6 to 9.

[0213] Aspect 82. The polymer, defined in any of aspects 67-81, wherein the ethylene polymer has a CY-a parameter in any range disclosed in this document, for example, from 0.1 to 0.3, from 0.13 to 0.2, from 0.13 to 0.17, from 0.16 to 0.26, from 0.17 to 0.24 or from 0.18 to 0.22.

[0214] Aspect 83. The polymer, defined in any of aspects 67-82, wherein the ethylene polymer comprises an ethylene homopolymer and / or an ethylene / α-olefin copolymer.

[0215] Aspect 84. The polymer, defined in any of aspects 67-83, wherein the ethylene polymer comprises an ethylene homopolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer and / or an ethylene / 1-octene copolymer.

[0216] Aspect 85. The polymer, defined in any of aspects 67-84, wherein the ethylene polymer comprises an ethylene / 1-hexene copolymer.

[0217] Aspect 86. The polymer, defined in any one of aspects 67-85, produced by the process defined in any one of aspects 38-66.

[0218] Aspect 87. An article comprising the polymer ethylene, as defined in either of aspects 67-86.

[0219] Aspect 88. An article comprising ethylene polymer, as defined in any one of aspects 67–86, wherein the article is an agricultural film, a geomembrane film, a packaging film, a pallet wrapping film, a part of Petition 870250088394, dated 09 / 30 / 2025, pp. 160 / 171 73 / 73 automobile, a bottle, a container for chemicals, a drum, a fiber or fabric, a film or food packaging container, a food service article, a fuel tank, a geomembrane, a household container, a liner, a molded product, a medical device or material, an outdoor storage product, outdoor recreational equipment, a tab, a sheet or tape, a toy or a traffic barrier. Petition 870250088394, dated 09 / 30 / 2025, pages 161 / 171

Claims

1 / 6 CLAIMS 1. Process for producing an activated chromium catalyst, the process characterized by comprising: (i) placing a pre-catalyst in contact with a first inert atmosphere at a temperature T1 in a range of 500 °F to 700 °F (260 °C to 371 °C), wherein the pre-catalyst comprises a silica support and: 0.1 to 5% by weight of chromium; 0.1 to 10% by weight of titanium; and 1 to 5 mol of nitrogen / mol of titanium;(ii) subjecting the precatalyst to cycles of a first oxidizing atmosphere at a temperature T2 in a range of 500 °F to 700 °F (260 °C to 371 °C) and a second inert atmosphere at a temperature T3 in a range of 700 °F to 900 °F (371 °C to 482 °C), wherein the first oxidizing atmosphere causes an exothermic temperature increase from T2 to T3, thus triggering the introduction of the second inert atmosphere which results in cooling to T2, until the exothermic temperature increase in the first oxidizing atmosphere is less than or equal to 50 °F (28 °C) within 15 min or when heat must be added to maintain T3 in the presence of the first oxidizing atmosphere; (iii) heat the precatalyst in a third inert atmosphere at a temperature T4 in a range of 1000 °F to 1400 °F (538 °C to 760 °C) and hold the precatalyst at T4 in the third inert atmosphere for a retention time t1 in a range of 1 h to 15 h;(iv) cool the pre-catalyst in a fourth inert atmosphere to a temperature T5 in a range of 900 °F to 1200 °F (482 °C to 649 °C), where T5 is lower than T4; (v) subject the pre-catalyst to a second oxidizing atmosphere at T5 for a retention time t2 in a range of 30 min to 10 h; (vi) cool in a third oxidizing atmosphere to a temperature T6 in a range of 500 °F to 700 °F (260 °C to 371 °C) to produce the activated chromium catalyst; and (vii) purge the activated chromium catalyst in a fifth inert atmosphere at T6 and cool to room temperature.

2. Process according to claim 1, characterized in that: the amount of chromium in the precatalyst in an oxidation state of +5 or less is at least 70% by weight; and the amount of chromium in the activated chromium catalyst in a hexavalent oxidation state is at least 50% by weight.

3. Process, according to claim 1 or 2, characterized by further comprising, before step (i), a step of loading and heating the pre-catalyst in the first inert atmosphere up to T1.

4. A process according to any one of claims 1-3, characterized in that the first inert atmosphere, the third inert atmosphere, the fourth inert atmosphere, the fifth inert atmosphere and the sixth inert atmosphere are the same or different and independently comprise nitrogen, argon or a combination thereof.

5. Process, according to any one of claims 1-4, characterized in that the second inert atmosphere in each cycle of step (ii) is the same or different and independently comprises nitrogen, argon or a combination thereof.

6. A process according to any one of claims 1-5, characterized in that the second oxidizing atmosphere and the third oxidizing atmosphere independently comprise oxygen, air, a mixture of oxygen and an inert gas, a mixture of air and an inert gas, or a combination thereof.

7. Process according to any one of claims 1-6, characterized in that the first oxidizing atmosphere in each cycle of step (ii) is the same as or different from and independently comprises oxygen, air, a mixture of oxygen and an inert gas, a mixture of air and an inert gas, or a combination thereof.

8. Process, according to any of claims 1-7, Petition 870250088394, dated 09 / 30 / 2025, pp. 163 / 171 3 / 6 characterized by step (ii) comprising 2 to 10 cycles.

9. Process, according to any one of claims 1-8, characterized in that t2 is a time period sufficient to form at least 50% by weight of chromium (VI), based on the amount of chromium in the activated chromium catalyst.

10. Process, according to any one of claims 1-9, characterized in that the activated catalyst has a higher melting index potential than that of a control catalyst.

11. Olefin polymerization process characterized by comprising: (I) carrying out the process to produce the activated chromium catalyst according to any of claims 1-10; and (II) placing the activated chromium catalyst and an optional cocatalyst in contact with an olefin monomer and an optional olefin comonomer in a polymerization reactor system under polymerization conditions to produce an olefin polymer.

12. Process according to claim 11, characterized in that the olefin monomer comprises ethylene.

13. Process according to claim 11, characterized in that the activated chromium catalyst is brought into contact with ethylene and an olefin comonomer comprising 1-butene, 1-hexene, 1-octene or a mixture thereof.

14. Process, according to any one of claims 11-13, characterized in that the polymerization reactor system comprises a fluid paste reactor, a gas phase reactor, a solution reactor or a combination thereof.

15. Process, according to any one of claims 11-14, characterized in that the polymerization reactor system comprises a closed-cycle fluid paste reactor.

16. Process, according to any of claims 11-15, Petition 870250088394, dated 09 / 30 / 2025, pp. 164 / 171 4 / 6 characterized by the olefin polymer comprising an ethylene homopolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer and / or an ethylene / 1-octene copolymer.

17. Ethylene polymer characterized by having: a melt index (MI) in a range of 0.1 to 1 g / 10 min and / or a high-charge melt index (HLMI) in a range of 10 to 80 g / 10 min; a density in a range of 0.93 to 0.96 g / cm3; and a total film gel count of less than or equal to 40 gels per ft2 of 25 micron thick film, wherein the film gels span a diameter size greater than 200 µm; wherein the ethylene polymer contains: 150 to 680 ppm of silica; 1.5 to 6.8 ppm of chromium; and 1.5 to 40 ppm of titanium.

18. Polymer according to claim 17, characterized in that the ethylene polymer has a MI in a range of 0.1 to 1 g / 10 min, 0.1 to 0.75 g / 10 min, 0.1 to 0.6 g / 10 min, 0.2 to 1 g / 10 min, 0.2 to 0.6 g / 10 min or 0.3 to 0.6 g / 10 min.

19. Polymer, according to claim 17 or 18, characterized in that the ethylene polymer has an HLMI in a range of 10 to 80 g / 10 min, 10 to 70 g / 10 min, 10 to 60 g / 10 min, 10 to 50 g / 10 min, 20 to 80 g / 10 min, 20 to 50 g / 10 min or 30 to 50 g / 10 min.

20. Polymer, according to any one of claims 17-19, characterized by its density being in a range of 0.93 to 0.956 g / cm3, 0.934 to 0.96 g / cm3, 0.934 to 0.956 g / cm3, 0.934 to 0.95 g / cm3 or 0.945 to 0.958 g / cm3.

21. Polymer, according to any of claims 17-20, characterized in that the total film gel count is less than or equal to 30 gels per ft² of 25 micron thick film, less than or equal to 20 gels per ft² of 25 micron thick film, less than or equal to 10 gels per ft² of 25 micron thick film, less than or equal to 8 gels per ft² of 25 micron thick film, or less than or equal to 5 gels per ft² of 25 micron thick film.

22. Polymer, according to any one of claims 17-21, characterized in that the ethylene polymer has a catalyst particle gel count of less than or equal to 40 gels per ft² of 25 micron thick film, less than or equal to 30 gels per ft² of 25 micron thick film, less than or equal to 20 gels per ft² of 25 micron thick film, less than or equal to 10 gels per ft² of 25 micron thick film, less than or equal to 8 gels per ft² of 25 micron thick film, or less than or equal to 5 gels per ft² of 25 micron thick film, wherein the catalyst particle gels encompass a diameter size greater than 200 µm and are caused by catalyst particles.

23. Polymer, according to any one of claims 17-22, characterized by the ethylene polymer containing: 180 to 600 ppm, 200 to 680 ppm, 200 to 600 ppm, 200 to 500 ppm, 200 to 400 ppm, 150 to 600 ppm, 150 to 500 ppm or 150 to 450 ppm of silica; or 1.8 to 6 ppm, 2 to 6.8 ppm, 2 to 6 ppm, 2 to 5 ppm, 2 to 4.5 ppm, 2 to 4 ppm, 1.5 to 6 ppm, 1.5 to 5.5 ppm, 1.5 to 5 ppm or 3 to 6 ppm of chromium; or 1.5 to 30 ppm, 2 to 40 ppm, 2 to 30 ppm, 2 to 10 ppm, 3 to 30 ppm, 3 to 20 ppm, 3 to 10 ppm, 4 to 20 ppm, 5 to 40 ppm, 5 to 25 ppm, 5 to 15 ppm, 7 to 17 ppm or 8 to 16 ppm of titanium; or any combination thereof.

24. Polymer, according to any one of claims 17-23, characterized in that the ethylene polymer independently contains less than 0.1 ppm by weight of Mg, V, Zr or Hf.

25. Polymer, according to any one of claims 17-24, characterized by the ethylene polymer comprising an ethylene homopolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer and / or an ethylene / 1-octene copolymer.

26. Polymer, according to any one of claims 17-25, characterized in that it is produced by the process according to any one of claims 11-16.

27. Article of polymer manufacturing composition characterized by conforming to any one of claims 17-26. Petition 870250088394, dated 09 / 30 / 2025, pp. 167 / 171

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