Peroxide treated blown polymers with increased reexpansion and constant mold release expansion

Abstract

The name of the invention is peroxide treated blown polymers with increased heavy expansion and constant mold release expansion. The ethylene-based polymers are generally characterized by a high load melt index of less than 12 g / 10 min, a weight average molecular weight of from 200,000 to 550,000 g / mol, a number average molecular weight of from 18,000 to 48,000 g / mol, a CY-a parameter of less than 0.12, a tan delta at 0.1 sec-1 of from 0.5 to 0.9 degrees, a tan delta at 100 sec-1 of from 0.5 to 0.75 degrees, and a viscosity at 0.001 sec-1 of from 1.3 x 106 to 1 x 107 Pa-sec. These ethylene polymers can be produced by peroxide treatment of bimodal molecular weight distribution dual metallocene catalyzed resins, and can be used to produce blown bottles and other blown products.

Description

[0001] This application is a divisional application. The application date of the original application is March 8, 2022, the application number is 2022800177593, and the invention name is "Peroxide-treated blown polymer with increased re-expansion and constant mold expansion". Technical Field

[0002] The present disclosure generally relates to peroxide treatment of bimodal polyolefin base resins to produce ethylene polymers, and the subsequent use of the ethylene polymers to form blow molded products with a beneficial combination of both die swell and weight swell. Background Art

[0003] Polyolefins, such as high-density polyethylene (HDPE) homopolymers and copolymers and linear low-density polyethylene (LLDPE) copolymers, can be produced using various combinations of catalyst systems and polymerization processes. Metallocene-based catalyst systems can, for example, produce ethylene polymers with good impact strength, tear resistance, and optical properties, but generally at the expense of poor extrusion processability and melt strength. Chromium-based catalyst systems can, for example, produce ethylene-based polymers that typically have good extrusion processability and polymer melt strength due to their broad molecular weight distribution (MWD).

[0004] In some end-use applications, such as blow molding, it can be difficult to produce ethylene polymers with acceptable levels of die swell and reswell, regardless of the catalyst system.Thus, the present invention is generally directed to these objects. Summary of the Invention

[0005] This summary is provided to introduce in simplified form a series of concepts that will be further described in the detailed description below. This summary is not intended to identify essential or essential features of the claimed subject matter. This summary is also not intended to limit the scope of the claimed subject matter.

[0006] The present invention generally relates to ethylene polymers (e.g., ethylene / α-olefin copolymers) characterized by a high load melt index (HLMI) less than or equal to 12 g / 10 min, a weight average molecular weight (Mw) in the range of 200,000 to 550,000 g / mol, a number average molecular weight (Mn) in the range of 18,000 to 48,000 g / mol, a CY-a parameter less than or equal to 0.12, a 0.1 sec -1 tanδ (tan d or tangent δ) under 0.5 to 0.75 degrees in 100sec -1 tanδ at 1.3×10 6 to 1×107 Within 0.001sec in the Pa-sec range -1 Viscosity (at 0.001sec -1 Eta or 0.001sec -1 These ethylene polymers can be used to produce a variety of articles, such as blow molded bottles and other blow molded products.

[0007] Ethylene polymer can be for example produced by comprising making base resin (for example, ethylene copolymer) contact with the method for producing ethylene polymer with peroxide compound.In some respects, described contacting step can comprise the step of melt processing blend or the mixture of base resin and peroxide compound under suitable melt processing temperature, and usually, based on the weight of base resin, the amount of peroxide group is in the scope of 10 to 500ppm, 25 to 400ppm or 50 to 350ppm.Although not limited to this, base resin can be characterized by following item usually: HLMI in the scope of 2 to 40g / 10min, Mw in the scope of 250,000 to 550,000g / mol, CY-a parameter in the scope of 0.12 to 0.3, 0.1sec in the scope of 0.8 to 1.05 degree. -1 Tanδ under 0.4 to 0.6 degrees in 100sec -1 tanδ under 1×10 5 to 3×10 6 Within 0.001sec in the Pa-sec range -1 The viscosity below.

[0008] The foregoing summary of the invention and the following detailed description all provide examples and are illustrative only. Therefore, the foregoing summary of the invention and the following detailed description should not be considered restrictive. In addition, features or variations other than those described herein may also be provided. For example, certain aspects and embodiments may relate to various feature combinations and sub-combinations described in the detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Presented are graphs of the molecular weight distributions of the ethylene polymers of Examples 1-6.

[0010] Figure 2 Presented are graphs of the molecular weight distributions of the ethylene polymers of Examples 7-12.

[0011] Figure 3 Presented are graphs of the molecular weight distributions of the ethylene polymers of Examples 13-17.

[0012] Figure 4Differential dynamic rheograms at 190°C are presented, showing the rheological differences between Examples 2-6 and the baseline of Example 1 at different shear rates.

[0013] Figure 5 Differential dynamic rheograms at 190°C are presented, showing the rheological differences between Examples 8-12 and the baseline of Example 7 at different shear rates.

[0014] Figure 6 Differential dynamic rheograms at 190°C are presented, showing the rheological differences between Examples 14-17 and the baseline of Example 13 at different shear rates.

[0015] Figure 7 Graphs of die swell and reswell based on peroxide loading are presented for Examples 1-6.

[0016] Figure 8 Graphs of die swell and reswell based on peroxide loading are presented for Examples 7-12.

[0017] definition

[0018] In order to more clearly define the terms used herein, the following definitions are provided. Unless otherwise indicated, the following definitions apply to the present disclosure. If the term is used in the present disclosure, but is not specifically defined in this article, the definition from IUPAC Chemical Terminology (Compendium of Chemical Terminology), the 2nd edition (1997) can be applied, as long as the definition does not conflict with any other disclosure or the definition used herein or makes any claim applying the definition unclear or infeasible. If any definition or usage provided by any file incorporated herein by reference conflicts with the definition or usage provided herein, then the definition or usage provided herein shall be the standard.

[0019] Herein, features of the subject matter are described such that within a particular aspect, combinations of different features are contemplated. For each and every aspect and / or feature disclosed herein, all combinations are contemplated that do not adversely affect the designs, compositions, and / or methods described herein, with or without explicit description of a particular combination. Additionally, unless expressly stated otherwise, any aspects and / or features disclosed herein may be combined to describe inventive features consistent with the present disclosure.

[0020] Although compositions and methods are described herein as "comprising" various components or steps, unless otherwise stated, the compositions and methods can also "consist essentially of" or "consist of" the various components or steps.

[0021] Unless otherwise indicated, the terms "a / an," "the," and the like are intended to include multiple alternatives, such as at least one. For example, unless otherwise indicated, disclosure of "additive" or "comonomer" is intended to encompass one additive or comonomer, or a mixture or combination of more than one additive or comonomer, respectively.

[0022] In general, element groups are referred to using the numbering scheme indicated in the version of the periodic table published in Chemical and Engineering News, 63(5), 27, 1985. In some cases, element groups may be referred to using the common name assigned to the group; for example, alkali metals refer to Group 1 elements, alkaline earth metals refer to Group 2 elements, transition metals refer to Groups 3-12 elements, and halogens or halide ions refer to Group 17 elements.

[0023] For any particular compound disclosed herein, unless otherwise indicated, the general structure or name presented is also intended to encompass all structural isomers, conformers, and stereoisomers that may result from a particular set of substituents. Thus, unless otherwise explicitly indicated, a compound generally referred to includes all structural isomers; for example, a general reference to pentane includes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane, while a general reference to butyl includes n-butyl, sec-butyl, isobutyl, and tert-butyl. In addition, when the context permits or requires, reference to the general structure or name encompasses all enantiomers, diastereomers, and other optical isomers (whether in enantiomeric or racemic form), as well as mixtures of stereoisomers. For any specific formula or name provided, any general formula or name provided also encompasses all conformers, regioisomers, and stereoisomers that may result from a particular set of substituents.

[0024] The term "polymer" is generally used herein to include olefin homopolymers, copolymers, terpolymers, etc., as well as their alloys and blends. The term "polymer" also includes impact, block, graft, random and alternating copolymers. Copolymers are derived from olefin monomers and one olefin comonomer, while terpolymers are derived from olefin monomers and two olefin comonomers. Therefore, "polymer" encompasses copolymers and terpolymers derived from any olefin monomer and comonomer disclosed herein. Similarly, the scope of the term "polymerization" includes homopolymerization, copolymerization and terpolymerization. Therefore, ethylene polymers include ethylene homopolymers, ethylene copolymers (e.g., ethylene / α-olefin copolymers), ethylene terpolymers, etc., as well as their blends or mixtures. Therefore, ethylene polymers encompass polymers commonly referred to in the art as LLDPE (linear low density polyethylene) and HDPE (high density polyethylene). For example, olefin copolymers (such as ethylene copolymers) can be derived from ethylene and comonomers, such as 1-butene, 1-hexene or 1-octene. If the monomer and comonomer are ethylene and 1-hexene, respectively, the resulting polymer can be classified as an ethylene / 1-hexene copolymer. Unless otherwise specified, the term "polymer" also includes all possible geometric configurations, and such configurations can include isotactic, syndiotactic, and atactic symmetries. In addition, the "polymers" disclosed herein (e.g., ethylene polymers, base resins) may also be referred to herein as "polymer compositions."

[0025] As used herein, the term "contacting" refers to materials or components that can be blended, mixed, slurried, dissolved, reacted, treated, compounded, or otherwise contacted or combined by some other means or by any suitable method. Unless otherwise indicated, the materials or components can be contacted together in any order, in any manner, and for any length of time.

[0026] Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the typical methods, devices, and materials are described herein.

[0027] All publications and patents mentioned herein are incorporated herein by reference for the purpose of describing and disclosing, for example, the constructs and methodologies that are described in the publications, which might be used in connection with the presently described invention.

[0028] The present invention discloses several types of scopes. When disclosing or claiming any type of scope, it is intended to disclose or claim separately each possible numeral that such scope can reasonably encompass, including the endpoints of the scope and any subrange and the combination of subranges encompassed therein. As a representative example, in various aspects of the present invention, the Mw / Mn ratio of ethylene polymer can be in certain ranges. By disclosing that the Mw / Mn ratio can be in the range of 6.5 to 20, it is intended to narrate that the Mw / Mn ratio can be any ratio in the range, and for example can be included in any range or combination within the range of 6.5 to 20, such as 7 to 17, 7.5 to 15 or 8 to 13 or the like. Equally, all other scopes disclosed herein should be interpreted in a manner similar to this example.

[0029] In general, an amount, size, formulation, parameter, range, or other quantity or characteristic is "about" or "approximately" whether or not expressly stated as such. Whether or not modified by the term "about" or "approximately," the claims include equivalents to the quantities or characteristics. DETAILED DESCRIPTION

[0030] The present invention generally relates to high molecular weight ethylene-based polymers having excellent melt strength and broad molecular weight distribution. Such polymers can be converted on blow molding equipment to form various articles.

[0031] The polymer expansion characteristics when leaving the accumulator head in the operation of the blow molding equipment are critical. Proper expansion is required to properly fill the mold and ensure that the part has the appropriate weight (e.g., appropriate wall thickness). The polymer expansion characteristics cover two different expansion behaviors: die expansion and re-expansion. It is known in the industry that changing the polymer structure to increase expansion simultaneously increases die expansion (e.g., how far the diameter of the polymer parison expands when leaving the accumulator head) and re-expansion (e.g., how much polymer flows into the parison itself and increases the parison wall thickness compared to the die gap opening). Whether the polymer is a unimodal chromium-based resin or a bimodal bismetallocene-based resin, changes in the polymer structure (such as molecular weight distribution) simultaneously increase or simultaneously reduce die expansion and re-expansion.

[0032] Surprisingly and advantageously, the disclosed ethylene polymers (which have been treated with 10-300 ppm of active peroxide groups) exhibit divergence or decoupling of die swell and reswell properties. In particular, while die swell is held constant, reswell surprisingly increases with increasing amounts of peroxide. Thus, reswell can surprisingly be increased or decreased without affecting die swell, thereby allowing blow molding equipment operators to independently control part weight (e.g., part wall thickness).

[0033] Ethylene polymers

[0034] In general, the polymers disclosed herein are ethylene-based polymers or ethylene polymers, encompassing homopolymers of ethylene and copolymers, terpolymers, and the like of ethylene and at least one olefin comonomer. Comonomers copolymerizable with ethylene typically have from 3 to 20 carbon atoms in their molecular chains. For example, typical comonomers may include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and the like, or combinations thereof. In one aspect, olefin comonomers may include C3-C 18 olefins; alternatively, the olefin comonomer may include C3-C 10 olefins; alternatively, the olefin comonomer may include C4-C 10 olefins; alternatively, the olefin comonomer may include C3-C 10 α-olefins; alternatively, the olefin comonomer may include C4-C 10 α-olefins; alternatively, the olefin comonomer may include 1-butene, 1-hexene, 1-octene, or any combination thereof; or alternatively, the comonomer may include 1-hexene.

[0035] In one aspect, the ethylene polymers of the present invention may comprise ethylene / α-olefin copolymers, while in another aspect, the ethylene polymers may comprise ethylene homopolymers, and in yet another aspect, the ethylene polymers of the present invention may comprise ethylene / α-olefin copolymers and ethylene homopolymers. For example, the ethylene polymers may comprise ethylene / 1-butene copolymers, ethylene / 1-hexene copolymers, ethylene / 1-octene copolymers, ethylene homopolymers, or any combination thereof; alternatively, ethylene / 1-butene copolymers, ethylene / 1-hexene copolymers, ethylene / 1-octene copolymers, or any combination thereof; or alternatively, ethylene / 1-hexene copolymers.

[0036] Illustrative and non-limiting examples of the ethylene polymers described herein (e.g., ethylene / α-olefin copolymers) have a high load melt index (HLMI) less than or equal to 12 g / 10 min, a weight average molecular weight (Mw) in the range of 200,000 to 550,000 g / mol, a number average molecular weight (Mn) in the range of 18,000 to 48,000 g / mol, a CY-a parameter less than or equal to 0.12, a 0.1 sec t-score in the range of 0.5 to 0.9 degrees, and a 0.1 sec t-score of 0.1 to 0.9 degrees. -1 tanδ (tan d or tangent δ) under 0.5 to 0.75 degrees in 100sec -1 tanδ (tan d or tangent δ) under 1.3×10 6 to 1×10 7 Within 0.001sec in the Pa-sec range -1 Viscosity (at 0.001sec-1 ETA or under 0.001sec -1 Unless otherwise indicated, this illustrative and non-limiting example of an ethylene polymer may also have any of the polymer characteristics listed below and in any combination.

[0037] Ethylene polymers have very low melt indexes, as indicated by a high load melt index (HLMI) of less than or equal to 12 g / 10 min. In some aspects, the HLMI of ethylene polymers can be less than or equal to 10 or less than or equal to 8 g / 10 min. Typical ranges of HLMI include 1 to 12 g / 10 min, 1 to 10 g / 10 min, 1 to 8 g / 10 min, 2 to 12 g / 10 min, or 2 to 10 g / 10 min, etc.

[0038] In one aspect, the ethylene polymer can have an Mw in the range of 200,000 to 500,000 g / mol, 250,000 to 550,000 g / mol, 250,000 to 500,000 g / mol, 250,000 to 475,000 g / mol, 275,000 to 550,000 g / mol or 275,000 to 475,000 g / mol. Additionally or alternatively, the ethylene polymer can have an Mw / Mn ratio falling within the range of 6.5 to 20 (such as 7 to 17, 7.5 to 15 or 8 to 13). Additionally or alternatively, the ethylene polymer can have an Mz / Mw ratio falling within the range of 4 to 9 (such as 4 to 8, 4.5 to 7.5 or 5 to 7).

[0039] In one aspect, ethylene polymers can have an Mp within the range of 60,000 to 110,000 g / mol, 65,000 to 105,000 g / mol or 70,000 to 100,000 g / mol. Additionally or alternatively, ethylene polymers can have an Mn within the range of 20,000 to 46,000 g / mol, 22,000 to 46,000 g / mol, 20,000 to 42,000 g / mol or 22,000 to 40,000 g / mol. Additionally or alternatively, ethylene polymers consistent with some aspects of the present invention can have a bimodal molecular weight distribution (as determined using gel permeation chromatography (GPC) or other related analytical techniques) conventionally. Generally speaking, in bimodal molecular weight distribution, there is a valley between peaks, and the peaks can be separated or deconvoluted. Typically, a bimodal molecular weight distribution can be characterized as having an identifiable high molecular weight component (or distribution) and an identifiable low molecular weight component (or distribution). Illustrative unimodal and bimodal MWD curves are shown in U.S. Patent No. 8,383,754, which is incorporated herein by reference in its entirety.

[0040] The ethylene-based polymers disclosed herein generally have a density greater than or equal to 0.935 g / cm 3 , and less than or equal to 0.965g / cm 3 However, in certain aspects, the density can be between 0.94 and 0.965 g / cm 3 , 0.945 to 0.965 g / cm 3 , 0.94 to 0.96 g / cm 3 , 0.945 to 0.96 g / cm 3 , 0.95 to 0.965 g / cm 3 or 0.95 to 0.96 g / cm 3 within the range.

[0041] The ethylene polymers described herein have high viscosity at low shear rates, which translates into excellent polymer melt strength. -1 Viscosity (at 0.001sec -1 ETA or under 0.001sec -1 The η) under the condition of 6 to 1×10 7 Pa-sec range, such as 1.3×10 6 to 6×10 6 Pa-sec; alternatively, 1.3×10 6 to 5×10 6 Pa-sec; alternatively, 1.5×10 6 to 1×10 7 Pa-sec; alternatively, 1.5×10 6 to 6×10 6 Pa-sec; alternatively, 1.5×10 6 to 5×10 6 Pa-sec; alternatively, 2×10 6 to 6×10 6 Pa-sec; or alternatively, 2×10 6 to 5×10 6 Pa-sec. In some aspects, the ethylene polymer may have a 8 to 1×10 30 Pa-sec, 1×10 8 to 1×10 28 Pa-sec, 1×10 10 to 1×10 30 Pa-sec, 1×10 10 to 1×10 27 Pa-sec, or 1×1012 to 1×10 27 The ethylene polymer may have a zero shear viscosity (η0) at 190°C in the range of Pa-sec etc. Additionally or alternatively, the ethylene polymer may have a zero shear viscosity (η0) at 190°C in the range of 5×10 3 to 1×10 25 s range (such as 6×10 3 to 1×10 23 sec, 1×10 5 to 1×10 25 sec, 1×10 5 to 1×10 23 sec, or 1×10 7 to 1×10 23 s, etc.) relaxation time (τ η ). Zero shear viscosity and relaxation time were determined from viscosity data measured at 190°C and using the Carreau-Yasuda (CY) empirical model (with creep adjustment) as described herein.

[0042] The ethylene polymer can have a CY-a parameter less than or equal to 0.12 (e.g., less than or equal to 0.11, less than or equal to 0.1, less than or equal to 0.08, or less than or equal to 0.06). Typically, ranges include 0.01 to 0.12, 0.01 to 0.1, 0.01 to 0.08, or 0.01 to 0.06, etc. Additionally or alternatively, the ethylene polymer can have a CY-a parameter in the range of 0.5 to 0.9 degrees in one aspect, 0.5 to 0.85 degrees in another aspect, 0.5 to 0.8 degrees in another aspect, 0.55 to 0.9 degrees in another aspect, 0.55 to 0.85 degrees in another aspect, 0.6 to 0.9 degrees in another aspect, 0.6 to 0.85 degrees in yet another aspect, and 0.6 to 0.8 degrees in yet another aspect. -1 Additionally or alternatively, the ethylene polymer may have a tan delta at 100 sec in the range of 0.5 to 0.75 degrees in one aspect, 0.5 to 0.72 degrees in another aspect, 0.5 to 0.7 degrees in another aspect, 0.52 to 0.75 degrees in another aspect, 0.52 to 0.72 degrees in another aspect, 0.52 to 0.7 degrees in another aspect, 0.55 to 0.75 degrees in yet another aspect, and 0.55 to 0.72 degrees in yet another aspect. -1 Additionally or alternatively, the ethylene polymer may have a tan δ at 190° C. in the range of 1700 to 3300 Pa-sec, 1800 to 3200 Pa-sec, 1900 to 3100 Pa-sec, or 2000 to 3000 Pa-sec. -1The viscosity at 100°C (eta at 100°C or η at 100°C). These rheological parameters are determined from viscosity data measured at 190°C and using the Carreau-Yasuda (CY) empirical model (with creep adjustment) described herein.

[0043] In addition, ethylene polymers can have a reverse comonomer distribution, generally, the comonomer incorporation of the higher molecular weight component of the polymer is higher than the comonomer incorporation of the lower molecular weight component. Typically, as the molecular weight increases, the comonomer incorporation increases. In one aspect, the number of short chain branches (SCBs) per 1000 total carbon atoms of a polymer can be greater at Mw than at Mn. In another aspect, the number of SCBs per 1000 total carbon atoms of a polymer can be greater at Mz than at Mw. In another aspect, the number of SCBs per 1000 total carbon atoms of a polymer can be greater at Mz than at Mn.

[0044] In one aspect, the ethylene polymers described herein can be a reactor product (e.g., a single reactor product), e.g., rather than a post-reactor blend of, for example, two polymers having different molecular weight characteristics. Those skilled in the art will readily recognize that a physical blend of two different polymer resins can be prepared, but this requires additional processing and complexity not required for a reactor product.

[0045] In addition, ethylene polymers can be produced from base resins that can be prepared using a dual metallocene catalyst system. Ziegler-Natta and chromium-based catalyst systems are not required. Therefore, the ethylene polymers can be free of measurable amounts of chromium or titanium or vanadium or magnesium (catalyst residues), i.e., less than 0.1 ppm by weight. In some aspects, the ethylene polymers can independently contain less than 0.08 ppm, less than 0.05 ppm, or less than 0.03 ppm of chromium (or titanium, or vanadium, or magnesium).

[0046] The ethylene polymer may be in any suitable form, such as fluff, powder, granules, pellets, etc. Typically, the ethylene polymer is in the form of pellets. The ethylene polymer may contain one or more additives, non-limiting examples of which may include antioxidants, acid scavengers, anti-caking additives, slip additives, colorants, fillers, processing aids, ultraviolet inhibitors, and the like, and combinations thereof.

[0047] Aspects of the present invention also relate to the performance of these ethylene polymers (for example, ethylene / 1-hexene copolymer) on representative blow molding equipment, as described below.Advantageously, ethylene polymers can have and die expansion (as quantitatively by the flat bottom in inch) decoupling weight causing expansion (as quantitatively by the part weight in gram), and the difference between the two can depend on the amount of the peroxide for the production of ethylene polymers.In one aspect, for example, ethylene polymers can have 200 to 280, in another aspect 210 to 270, in another aspect 230 to 280 and in another aspect 230 to 270 scopes weight causing expansion and die expansion (by quantitatively the weight of part weight in gram and by the quantitative die expansion of the flat bottom in inch) ratio.Equally advantageously, ethylene polymers has unusual melt strength during blow molding, and it can be quantitatively by at least 40sec and more generally at least 50s or at least 100sec hanging time (hangtime).

[0048] Consistent with aspects of the present invention, ethylene polymers can be produced from a base resin (discussed herein below) via a method comprising contacting the base resin with a peroxide compound to produce an ethylene polymer (any ethylene polymer disclosed herein). In general, the amount of the peroxide compound used in the method (ppm by weight) is less interesting because the amount of the peroxide groups is more important, and the molecular weight and number of peroxide groups of each peroxide compound are inconsistent among all suitable peroxide compounds. In general, based on the weight of the base resin, the amount of the peroxide groups can be in the range of 10 to 500 ppm, 25 to 400 ppm, 50 to 400 ppm, 50 to 350 ppm, 75 to 400 ppm, or 100 to 300 ppm of peroxide groups based on the weight of the base resin.

[0049] Thus, the base resin and the peroxide compound can be contacted at a temperature sufficient to generate peroxide groups at 10 to 500 ppm, 25 to 400 ppm, 50 to 400 ppm, 50 to 350 ppm, 75 to 400 ppm, or 100 to 300 ppm peroxide groups based on the weight of the base resin.

[0050] In one aspect, the step of contacting base resin with peroxide compound can comprise the blend (or mixture) of melt processing base resin and peroxide compound under any suitable melt processing temperature, and described melt processing temperature is for example the temperature in the range of 120 to 300 ℃, the temperature in the range of 150 to 250 ℃, the temperature in the range of 175 to 225 ℃ or the like.Suitable temperature can depend on the composition of peroxide compound and the temperature of its release peroxide group.Before contacting peroxide compound, base resin can be in any suitable form, comprise for example fluff, powder, particle, pellet, solution, slurry, emulsion etc.Similarly, peroxide compound can be in solid form, in liquid form, in solution or in slurry.A kind of specific method uses the masterbatch of peroxide compound, and contacts base resin (in fluff form) during melt processing.The masterbatch of peroxide compound can contain any suitable organic or inorganic carrier, but usually contains high melt flow carrier resin, such as polyethylene or polypropylene.

[0051] The present invention is not limited to any ad hoc method that base resin and peroxide compound are contacted and melt-processed base resin and peroxide compound.As those skilled in the art will recognize, can adopt various mixing and / or compounding methods.In one aspect, the melt processing of base resin and peroxide compound can be carried out in single screw extrusion system.In another aspect, the melt processing of base resin and peroxide compound can be carried out in twin screw extrusion system (for example, counter-rotating mixer or co-rotating twin screw extrusion system).Twin screw extrusion system can comprise any combination of feed element, melting element, mixing element and conveying element.For example, twin screw extrusion system can contain all or most of mixing element.

[0052] The peroxide compound may be any compound containing one or more peroxide (OO) groups, suitable examples of which may include, but are not limited to, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, dicumyl peroxide, tert-butylcumyl peroxide, n-butyl-4,4'-di(tert-butylperoxy)valerate, etc. The peroxide compound may be added, for example, as solid small particles, dissolved in mineral oil, or in liquid form.

[0053] One or more additives may also be added during the conversion of the base resin (and peroxide compound) to the ethylene polymer. Non-limiting examples of suitable additives may include antioxidants, acid scavengers, anti-caking additives, slip additives, colorants, fillers, processing aids, ultraviolet inhibitors, and the like. If desired, a combination of two or more additives may be contacted with the base resin and peroxide compound.

[0054] Products

[0055] Goods can be formed by ethylene polymer of the present invention (for example, ethylene copolymer) and / or can comprise ethylene polymer of the present invention (for example, ethylene copolymer), and are therefore encompassed in this article.For example, the goods that can comprise polymer of the present invention can include but not limited to agricultural film, auto parts, bottles, chemical containers, drums, fiber or fabric, food packaging film or container, food service products, fuel tanks, geomembranes, household containers, linings, molded products, medical devices or material, outdoor storage products (for example, the panel of outdoor shed wall), outdoor recreational equipment (for example, kayak, the base of basketball goal), pipes, sheets or adhesive tape, toys or traffic barriers etc. Various techniques can be adopted to form these goods.The limiting examples of these techniques comprise injection molding, blow molding, rotational molding, film extrusion, sheet extrusion, profile extrusion, thermoforming etc.In addition, conventionally additives and properties-correcting agents are added in these polymers, so that useful polymer processing or end-use product attributes are provided. Such processes and materials are described in Modern Plastics Encyclopedia, Vol. 72, No. 12, November 1995 issue; and Film Extrusion Manual—Process, Materials, Properties, TAPPI Press, 1992; the disclosures of which are incorporated herein by reference in their entireties. In some aspects of the invention, an article may comprise any of the ethylene polymers described herein, and the article may be or may comprise a blow molded product, such as a blow molded bottle.

[0056] base resin

[0057] In general, the base resin used to produce the ethylene polymer can be any homopolymer of ethylene, or a copolymer, terpolymer, etc. of ethylene and at least one olefin comonomer disclosed above for the ethylene polymer. Thus, the base resin may comprise an ethylene / α-olefin copolymer, while in another aspect, the base resin may comprise an ethylene homopolymer, and in yet another aspect, the base resin may comprise an ethylene / α-olefin copolymer and an ethylene homopolymer. Thus, the base resin may comprise an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, an ethylene / 1-octene copolymer, an ethylene homopolymer, or any combination thereof; alternatively, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, an ethylene / 1-octene copolymer, or any combination thereof; or alternatively, an ethylene / 1-hexene copolymer. Typically, for example, if the base resin is an ethylene / 1-hexene copolymer, the ethylene polymer produced from the base resin is also an ethylene / 1-hexene copolymer, although mixtures and combinations of various types of homopolymers and copolymers may be used.

[0058] In order to produce ethylene polymers having the properties and benefits disclosed herein, suitable base resins are used. Illustrative and non-limiting examples of base resins (e.g., ethylene copolymers) of the present invention may have a HLMI in the range of 2 to 40 g / 10 min, a Mw in the range of 250,000 to 550,000 g / mol, a CY-a parameter in the range of 0.12 to 0.3, a 0.1 sec -1 Tanδ under 0.4 to 0.6 degrees in 100sec -1 tanδ under 1×10 5 to 3×10 6 Within 0.001sec in the Pa-sec range -1 Unless otherwise indicated, this illustrative and non-limiting example of a base resin consistent with the present invention may also have any of the polymer characteristics listed below and in any combination.

[0059] In some aspects, the base resin used to produce the ethylene polymer can have a HLMI in the range of 2 to 20 g / 10 min, 2 to 12 g / 10 min, 4 to 40 g / 10 min, 4 to 20 g / 10 min, 4 to 15 g / 10 min, or 4 to 12 g / 10 min, among others.

[0060] In one aspect, the base resin can have an Mw in the range of 250,000 to 500,000 g / mol, 250,000 to 475,000 g / mol, 300,000 to 550,000 g / mol, or 300,000 to 500,000 g / mol. Additionally or alternatively, the base resin can have an Mw / Mn ratio falling within the range of 9 to 20, such as 11 to 19, 12 to 18, or 13 to 16. Additionally or alternatively, the base resin can have an Mz / Mw ratio falling within the range of 4 to 9, such as 5 to 8, 5 to 7.5, or 6 to 8.

[0061] In one aspect, base resin can have the Mp in the range of 60,000 to 110,000 g / mol, 65,000 to 105,000 g / mol or 65,000 to 100,000 g / mol. Additionally or alternatively, base resin can have the Mn in the range of 18,000 to 48,000 g / mol, 20,000 to 42,000 g / mol or 22,000 to 38,000 g / mol. Additionally or alternatively, the base resin for the production of ethylene polymers can have a bimodal molecular weight distribution (as determined using gel permeation chromatography (GPC) or other related analytical techniques). In general, in bimodal molecular weight distribution, there is a valley between peaks, and the peaks can be separated or deconvoluted. Typically, bimodal molecular weight distribution can be characterized as having an identifiable high molecular weight component (or distribution) and an identifiable low molecular weight component (or distribution). Illustrative unimodal and bimodal MWD curves are shown in US Patent No. 8,383,754, which is incorporated herein by reference in its entirety.

[0062] The base resins used to produce the ethylene polymers disclosed herein generally have a density greater than or equal to 0.935 g / cm 3 , and less than or equal to 0.965g / cm 3 However, in certain aspects, the density can be between 0.94 and 0.965 g / cm 3 , 0.945 to 0.965 g / cm 3 , 0.94 to 0.96 g / cm 3 , 0.945 to 0.96 g / cm 3 , 0.95 to 0.965 g / cm 3 or 0.95 to 0.96 g / cm 3 within the range.

[0063] For base resin, at 190℃, -1 Viscosity (at 0.001sec -1 ETA or under 0.001sec -1 The η) under the condition of 5 to 2×10 6 Pa-sec range; alternatively, 1×10 5 to 1.8×10 6 Pa-sec; alternatively, 8×10 5 to 3×10 6 Pa-sec; alternatively, 8×10 5 to 2×10 6 Pa-sec; or alternatively, 8×10 5to 1.8×10 6 In some aspects, the base resin may have a 6 to 1×10 9 Pa-sec, 1×10 6 to 2×10 8 Pa-sec, 4×10 6 to 1×10 9 Pa-sec, or 4×10 6 to 2×10 8 Zero shear viscosity (η0) at 190°C in the Pa-sec range. As with the ethylene polymers, viscosity data for the base resins were measured at 190°C and using the Carreau-Yasuda (CY) empirical model (with creep adjustment) as described herein.

[0064] Typical ranges for the CY-a parameter of the base resin include 0.12 to 0.25, 0.13 to 0.3, 0.13 to 0.25, or 0.14 to 0.25, etc. Additionally or alternatively, the base resin may have a CY-a parameter in the range of 0.5 to 0.85 degrees in one aspect, 0.8 to 1 degree in another aspect, 0.83 to 1.05 degrees in another aspect, 0.83 to 1 degree in yet another aspect, 0.85 to 1.05 degrees in yet another aspect, and 0.85 to 1 degree in yet another aspect. -1 Additionally or alternatively, the base resin may have a tan delta at 100 sec in the range of 0.4 to 0.58 degrees in one aspect, 0.4 to 0.55 degrees in another aspect, 0.45 to 0.6 degrees in another aspect, 0.45 to 0.58 degrees in yet another aspect, and 0.45 to 0.55 degrees in yet another aspect. -1 As described above, these rheological parameters are determined from viscosity data measured at 190° C. and using the Carreau-Yasuda (CY) empirical model (with creep adjustment) described herein.

[0065] The base resins described herein may have an inverse comonomer distribution, where, in general, the comonomer incorporation of the higher molecular weight component of the polymer is higher than the comonomer incorporation of the lower molecular weight component. Typically, as the molecular weight increases, the comonomer incorporation increases. In one aspect, the number of short chain branches (SCBs) per 1000 total carbon atoms of the polymer may be greater at Mw than at Mn. In another aspect, the number of SCBs per 1000 total carbon atoms of the polymer may be greater at Mz than at Mw. In yet another aspect, the number of SCBs per 1000 total carbon atoms of the polymer may be greater at Mz than at Mn.

[0066] In one aspect, the base resin can be a reactor product (e.g., a single reactor product), e.g., rather than a post-reactor blend of, for example, two polymers having different molecular weight characteristics. One skilled in the art will readily recognize that a physical blend of two different polymer resins can be prepared, but this requires additional processing and complexity not required for a reactor product.

[0067] The base resin can be produced using a dual metallocene catalyst system, thus eliminating the need for a Ziegler-Natta and chromium-based catalyst system. Thus, the base resin can contain no measurable amounts of chromium, titanium, vanadium, or magnesium (catalyst residues), i.e., less than 0.1 ppm by weight. In some aspects, the base resin can independently contain less than 0.08 ppm, less than 0.05 ppm, or less than 0.03 ppm of chromium (or titanium, or vanadium, or magnesium).

[0068] While one or more additives may be incorporated during the conversion of the base resin to the ethylene polymer, or during the conversion of the ethylene polymer to the blow molded product (or to other articles), the base resin may also contain one or more suitable additives. Non-limiting examples of suitable additives may include antioxidants, acid scavengers, anti-blocking additives, slip additives, colorants, fillers, processing aids, ultraviolet inhibitors, and the like. Combinations of two or more additives may be present in the base resin.

[0069] As described herein, the performance of the base resin on representative blow molding equipment can be characterized in one aspect by a ratio of reswell to die swell (reswell:die swell) in the range of 150 to 225, 180 to 225, or 170 to 200. In another aspect, the base resin can be characterized by having a hang time in the range of 10 to 45 sec, 15 to 45 sec, or 20 to 45 sec.

[0070] In accordance with aspects of the present invention, a dual metallocene catalyst system can be used to produce the base resin. Although not limited thereto, catalyst component I can comprise a suitable non-bridged metallocene compound, catalyst component II can comprise a suitable bridged metallocene compound, and the catalyst system can further comprise a suitable activator and optionally a suitable cocatalyst.

[0071] Referring first to catalyst component I, it can comprise a non-bridged zirconium or hafnium-based metallocene compound containing two cyclopentadienyl groups, two indenyl groups, or a cyclopentadienyl and indenyl groups. In one aspect, catalyst component I can comprise a non-bridged zirconium or hafnium-based metallocene compound containing two cyclopentadienyl groups. In another aspect, catalyst component I can comprise a non-bridged zirconium or hafnium-based metallocene compound containing two indenyl groups. In yet another aspect, catalyst component I can comprise a non-bridged zirconium or hafnium-based metallocene compound containing a cyclopentadienyl group and an indenyl group.

[0072] Reference is now made to catalyst component II, which may be a bridged metallocene compound. In one aspect, for example, catalyst component II may comprise a bridged zirconium or hafnium-based metallocene compound. In another aspect, catalyst component II may comprise a bridged zirconium or hafnium-based metallocene compound having an alkenyl substituent. In yet another aspect, catalyst component II may comprise a bridged zirconium or hafnium-based metallocene compound having an alkenyl substituent and a fluorenyl group. In yet another aspect, catalyst component II may comprise a bridged zirconium or hafnium-based metallocene compound having a cyclopentadienyl group and a fluorenyl group and having an alkenyl substituent on the bridging group and / or on the cyclopentadienyl group. In addition, catalyst component II may comprise a bridged metallocene compound having an aryl group on the bridging group.

[0073] In addition, the dual catalyst system contains an activator. For example, the catalyst system may contain an activator-support, an aluminoxane compound, an organic boron or organic borate compound, an ionizing ionic compound, or any combination thereof. The catalyst system may contain one or more than one activator. When present, the cocatalyst may include, but is not limited to, alkylborons, alkylaluminums, and alkylzinc compounds, such as tri-n-butylborane, tripropylborane, triethylborane, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride, ethoxydiethylaluminum, diethylaluminum chloride, dimethylzinc, diethylzinc, dipropylzinc, dibutylzinc, dineopentylzinc, or a combination thereof. Representative catalyst systems that can be used to produce base resins are disclosed in U.S. Patent Nos. 9,169,337, 9,273,170, 9,493,589, and 9,650,459, which are incorporated herein by reference in their entirety.

[0074] Base resins can be produced from these catalyst systems using any suitable olefin polymerization process, using various types of polymerization reactors, polymerization reactor systems, and polymerization reaction conditions. One such olefin polymerization process for polymerizing olefins in the presence of the catalyst composition of the present invention can comprise contacting the catalyst composition with ethylene and optionally olefin comonomer(s) in a polymerization reactor system under polymerization conditions to produce the base resin.

[0075] As used herein, "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. Various types of polymerization reactors include those that may be referred to as batch reactors, slurry reactors, gas phase reactors, solution reactors, high-pressure reactors, tubular reactors, autoclave reactors, and the like, or combinations thereof; or alternatively, the polymerization reactor system may comprise a slurry reactor, a gas phase reactor, a solution reactor, or a combination thereof. The polymerization conditions for various reactor types are well known to those skilled in the art. The gas phase reactor may comprise a fluidized bed reactor or a staged horizontal reactor. The slurry reactor may comprise a vertical or horizontal ring. The high-pressure reactor may comprise an autoclave reactor or a tubular reactor. The reactor type may comprise a batch process or a continuous process. The continuous process may use intermittent or continuous product discharge. The polymerization reactor system and process may also include partial or complete direct recycling of unreacted monomer, unreacted comonomer, and / or diluent.

[0076] The polymerization reactor system may also comprise a single reactor or multiple reactors (two reactors, more than two reactors, etc.) of the same or different types. For example, the polymerization reactor system may comprise a slurry reactor, a gas phase reactor, a solution reactor, or a combination of two or more of these reactors. The production of polymer in multiple reactors may comprise several stages in at least two separate polymerization reactors interconnected by a transfer device, so that the polymer produced from the first polymerization reactor can be transferred to the second reactor. The polymerization conditions required for one of the reactors may be different from the operating conditions of the other reactors. Alternatively, polymerization in multiple reactors may comprise manually transferring the polymer from one reactor to a subsequent reactor to continue polymerization. The multi-reactor system may comprise any combination, including but not limited to multiple loop reactors, multiple gas phase reactors, a combination of loop reactors and gas phase reactors, multiple high-pressure reactors, or a combination of a high-pressure reactor with a loop reactor and / or a gas phase reactor. The multiple reactors may be operated in series, in parallel, or in series and in parallel. Therefore, the present invention encompasses polymerization reactor systems comprising a single reactor, comprising two reactors, and comprising more than two reactors. In certain aspects of the present invention, the polymerization reactor system may comprise a slurry reactor, a gas phase reactor, a solution reactor, and a combination of multiple reactors thereof.

[0077] According to one aspect, the polymerization reactor system may include at least one loop slurry reactor comprising vertical or horizontal loops. Monomer, diluent, catalyst and comonomer can be continuously fed into the loop reactor where polymerization occurs. Generally speaking, a continuous process may include continuously introducing monomer / comonomer, catalyst and diluent into the polymerization reactor, and continuously removing a suspension comprising polymer particles and diluent from the reactor. The reactor effluent may be flash evaporated to remove solid polymer from a liquid comprising diluent, monomer and / or comonomer. Various techniques may be used for this separation step, including but not limited to flash evaporation, which may include any combination of heating and decompression, separation by the cyclonic action in a cyclone separator or hydrocyclone, or separation by centrifugation.

[0078] Typical slurry polymerization processes (also known as particle form processes) are 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, each of which is incorporated herein by reference in its entirety.

[0079] Suitable diluents used in slurry polymerization include, but are not limited to, the monomer being polymerized and a hydrocarbon that is liquid under the 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 loop polymerizations can occur under bulk conditions without the use of a diluent.

[0080] According to another aspect, the polymerization reactor system may include at least one gas phase reactor (e.g., a fluidized bed reactor). Such reactor systems may use a continuous recycle stream containing one or more monomers that continuously circulates through a fluidized bed under polymerization conditions in the presence of a catalyst. The recycle stream may leave the fluidized bed and be recycled back into the reactor. Simultaneously, a polymer product may be taken out from the reactor, and new or fresh monomers may be added to replace the polymerized monomers. Such gas phase reactors may include a multi-step gas phase polymerization process for olefins, wherein the olefins are gas phase polymerized in at least two independent gas phase polymerization zones, while the catalyst-containing polymer formed in the first polymerization zone is fed to a second polymerization zone. Representative gas phase reactors are disclosed in U.S. Patents 5,352,749, 4,588,790, 5,436,304, 7,531,606, and 7,598,327, each of which is incorporated herein by reference in its entirety.

[0081] According to yet another aspect, the polymerization reactor system can comprise a high-pressure polymerization reactor, for example, a tubular reactor or an autoclave reactor. The tubular reactor can have several zones where fresh monomer, initiator, or catalyst is added. Monomer can be entrained in an inert gas stream and introduced into one zone of the reactor. Initiator, catalyst, and / or catalyst components can be entrained in the gas stream and introduced into another zone of the reactor. The gas streams can be mixed for polymerization. Heat and pressure can be appropriately used to achieve optimal polymerization reaction conditions.

[0082] According to another aspect, the polymerization reactor system may include a solution polymerization reactor in which monomer / comonomer is contacted with the catalyst composition by suitable stirring or other means. A carrier comprising an inert organic diluent or excess monomer may be used. If desired, the monomer / comonomer may be contacted with the catalytic reaction product in the presence or absence of a liquid material in the gas phase. The polymerization zone may be maintained at a temperature and pressure such that a polymer solution is formed in the reaction medium. Stirring may be used to obtain better temperature control and to maintain a uniform polymerization mixture throughout the polymerization zone. Suitable means may be used to dissipate the exothermic heat of polymerization.

[0083] The polymerization reactor system can also include at least one feed system, at least one feed system for catalyzer or catalyst component and / or any combination of at least one polymer recovery system. Suitable reactor system can also include the system for raw material purification, catalyst storage and preparation, extrusion, reactor cooling, polymer recovery, fractional separation, recycling, storage, loading, laboratory analysis and process control. Depend on the desired characteristics of olefin polymers, hydrogen can be added in the polymerization reactor (for example, continuously, pulse etc.) as required.

[0084] The polymerization conditions that can be controlled to improve efficiency and provide desired polymer properties can include temperature, pressure and the concentration of various reactants.Polymerization temperature may affect catalyst productivity, polymer molecular weight and molecular weight distribution.For example, in order to produce a specific grade of olefin polymer (or ethylene polymer), various polymerization conditions can be kept substantially constant.According to the Gibbs free energy equation (Gibbs Free energy equation), suitable polymerization temperature can be any temperature lower than the depolymerization temperature.Typically, depending on the type of polymerization reactor, this includes, for example, 60 ℃ to 280 ℃ or 60 ℃ to 120 ℃.In some reactor systems, polymerization temperature generally can be in the range of 70 ℃ to 100 ℃ or 75 ℃ to 95 ℃.

[0085] Suitable pressure will also vary according to reactor and polymerization type. The pressure of the liquid phase polymerization in the loop reactor is typically less than 1000psig (6.9MPa). The pressure of gas phase polymerization is generally 200 to 500psig (1.4MPa to 3.4MPa). High pressure polymerization in tubular reactors or autoclave reactors is generally operated under 20,000 to 75,000psig (138 to 517MPa). Polymerization reactors can also operate in the supercritical region, which generally occurs under higher temperatures and pressures. Operations above the critical point (supercritical phase) of the pressure / temperature diagram can provide advantages for the polymerization process.

[0086] Consistent with aspects of the present invention, the olefin monomer used in the polymerization process is ethylene, and the comonomer may comprise C3-C 10 α-olefins; 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.

[0087] Example

[0088] The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the present invention in any way. After reading the description herein, those of ordinary skill in the art may come to various other aspects, embodiments, modifications, and equivalents thereof without departing from the spirit of the present invention or the scope of the appended claims.

[0089] The high load melt index (HLMI) was determined according to ASTM D1238 at 190°C with a 21.6 kg weight. 21 , g / 10 min). The values can be expressed in grams per cubic centimeter (g / cm3) according to ASTM D1505 and ASTM D4703 on compression molded samples cooled at 15°C per hour and conditioned at room temperature for 40 hours. 3 ) to determine the density.

[0090] Molecular weights and molecular weight distributions were obtained using a PL-GPC 220 (Polymer Labs, Agilent Company) system equipped with an IR4 detector (Polymer Char, Spain) and three (3) Styragel HMW-6E GPC columns (Waters, MA) operated at 145°C. The flow rate of the mobile phase 1,2,4-trichlorobenzene (TCB) containing 0.5 g / L 2,6-di-tert-butyl-4-methylphenol (BHT) was set to 1 mL / min, and the polymer solution concentration was approximately 1 mg / mL, depending on the molecular weight. Sample preparation was performed at 150°C with occasional and gentle stirring for a nominal 4 hr before the solution was transferred to a sample vial for injection. An injection volume of approximately 400 μL was used. Molecular weights and molecular weight distributions were derived using an integral calibration method using a broad HDPE polyethylene resin, MARLEX BHB5003, from Chevron Phillips Chemical Company, as a standard. The integral table for the standards was predetermined in a separate experiment using SEC-MALS. Mn is the number average molecular weight, Mw is the weight average molecular weight, Mz is the z average molecular weight, and Mp is the peak molecular weight (the molecular weight position of the highest point of the molecular weight distribution curve).

[0091] Melt rheological characterization was performed as follows. Small strain (10%) oscillatory shear measurements were performed on an Anton Paar MCR 501 rheometer using parallel plate geometry. All rheological tests were performed at 190°C. The complex viscosity |η*| versus frequency (ω) data were then curve-fitted using a modified three-parameter Carreau-Yasuda (CY) empirical model to obtain the zero shear viscosity – η0, the intrinsic viscosity relaxation time – τ, and the relative humidity. η and width parameter – a (CY-a parameter). The simplified Carreau-Yasuda (CY) empirical model is as follows.

[0092]

[0093] Where: |η*(ω)| = the magnitude of the composite shear viscosity,

[0094] η0 = zero shear viscosity;

[0095] τ η = viscosity relaxation time (τ(η), in sec);

[0096] a = "width" parameter (CY-a parameter);

[0097] n = fixed final power law slope, fixed at 2 / 11; and

[0098] ω = angular frequency of the oscillatory shear deformation.

[0099] Detailed information on the meaning 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, Vol. 1, Fluid Mechanics, 2nd ed., John Wiley & Sons (1987); each of which is incorporated herein by reference in its entirety.

[0100] Creep adjustment is used to extend the low frequency range of rheological characterization to 10 -4 sec -1 (Except for the differential dynamic rheograms constructed without creep adjustment). In the creep test, a constant shear stress σ0 is applied to the specimen, and the shear strain γ is recorded as a function of the creep time t. Although the time-dependent data produced by the creep and creep recovery tests appear different from the frequency-dependent data measured in the dynamic frequency sweep test, as long as the measurements are made in the linear viscoelastic regime, the two experimental data sets contain the same rheological information, so that the time-dependent creep compliance data can be converted into frequency-dependent dynamic data, and thus long-term creep measurements can complement the low-frequency data of the dynamic frequency sweep measurements. Details of the test methods and analysis can be found in Y. W. Inn and D. C. Rohlfing, "Application of creep test to obtain the linear viscoelastic properties at low frequency range for polyethylene melts," Applied Rheology 22 (2012), which is incorporated herein by reference in its entirety.

[0101] Using the generalized Voigt model with a delay time τ k and the discrete spectrum of zero shear rate viscosity η0 J k Modeling the time-dependent creep compliance J(t) = γ(t) / σ0,

[0102]

[0103] If the discrete delay spectrum accurately describes the compliance data, then the linear viscoelastic theory allows quantitative description of other types of experimental data, for example, the storage and loss compliances are calculated as

[0104]

[0105] From the relationship between composite modulus and composite compliance, the storage and loss moduli of dynamic frequency sweep data can be obtained as

[0106]

[0107] As a simple numerical method to obtain the discrete delay time spectrum, the Microsoft Excel solver tool can be used by minimizing the following objective function O.

[0108]

[0109] In order to reliably convert time-dependent creep data into frequency-dependent dynamic data, the frequency range needs to be limited by the test time of the creep measurement. If accurate experimental data can be obtained over the entire creep time range until the creep compliance reaches a steady state, then an accurate function of the delay spectrum over the entire time scale can also be calculated. However, obtaining such data for high molecular weight polymers with very long relaxation times is generally impractical. Creep data only contain information over a limited time range, so that the frequency range is limited by the duration t of the creep test. N The limit is that the effective information of frequency is N -1 The extrapolated data outside this frequency range may be affected by fitting artifacts.

[0110] For rheological measurements involving creep adjustment, the polymer samples were compression molded at 182°C for a total of 3 minutes. The samples were melted at relatively low pressure for 1 minute and then subjected to high molding pressure for 2 minutes. The molded samples were then quenched in a room temperature press and 25.4 mm diameter discs were then punched out from the molded plates for measurement in a rotational rheometer. Measured at 190°C in parallel plates of 25 mm diameter using a controlled stress rheometer (Physica MCR-501, Anton Paar) equipped with an air bearing system. The test chamber of the rheometer was purged with nitrogen to minimize oxidative degradation. After thermal equilibrium, the specimens were squeezed between the plates to a thickness of 1.6 mm and the excess was trimmed. A total of 8 minutes passed between the time the sample was inserted and the time the test was started. For dynamic frequency sweep measurements, the sample was tested at 0.0316 to 316 seconds. -1Small strains (1-10%) were applied to the linear viscoelastic regime at an angular frequency of 10,200 sec (170 min) to limit the total test time to 4 hours because of concerns about sample throughput and thermal stability. The low frequency range was extended to 10 by converting the time-dependent creep data into frequency-dependent dynamic data. -4 rad / sec, which is two orders of magnitude lower than the frequency range of the dynamic test. The Carreau-Yasuda model was used to curve fit the complex viscosity (|η*|) versus frequency (ω) data.

[0111] One of the main concerns in performing creep tests, and indeed any long-term measurements, is that the sample does not change significantly during the measurement (which may take hours to perform). If a polymer sample is heated for an extended period without appropriate thermal stabilization (e.g., antioxidants), changes in the polymer may occur, which can have a significant impact on the polymer's rheological behavior and its characterization. The polymer to be tested should have a thermal stability of at least 4-5 hours at 190°C under nitrogen; for example, ethylene polymers containing at least 0.4 wt.% antioxidant have been found to be sufficiently stable to obtain valid creep adjustment data.

[0112] For rheological measurements in parallel plates, the specimens are squeezed between the plates to a thickness of 1.6 mm and the excess is then trimmed. When the sample is trimmed with a large force in one direction, some residual stress is generated, resulting in strain drift. Therefore, creep testing should be avoided immediately after sample trimming, as residual stress can affect subsequent creep measurements, especially for highly viscoelastic resins with long relaxation times. If the applied stress of the creep test is not large enough, the strain generated may be very small, so that the creep results may be affected by the artifacts of strain drift. In order to minimize this effect, the sample is trimmed as gently as possible and the creep test is performed after a waiting time of 2000 seconds to allow any residual stress to relax.

[0113] The appropriate magnitude of the applied stress σ0 is important for reliable creep data. The stress σ0 must be small enough so that the strain will remain within the linear viscoelastic regime, and it must be large enough so that the strain signal is strong enough to provide satisfactory data resolution for good accuracy. Although not limited thereto, a suitable applied stress is equal to the complex modulus |G*| at a frequency of 0.01 rad / sec multiplied by 0.04.

[0114] At 190℃ in 0.001sec -1 The polymer viscosity at ΔV (referred to as η(0.001) or eta(0.001)) was determined with an Anton Paar MCR 501 rheometer using parallel plate geometry.

[0115] Short chain branching (SCB) content and short chain branching distribution (SCBD) across molecular weight distribution can be determined via a GPC system (IR5-GPC) detected by IR5, wherein the GPC system is a PL220 GPC / SEC system (Polymer Labs, Agilent company) equipped with three Styragel HMW-6E columns (Waters, MA) for polymer separation. A detailed description of the method can be found in the literature (Y. Yu, A Short-Chain Branching Distribution Determination Technique for Polyethylene Using IR5-Detected GPC, Macromolecular Symposia, 2020, 390, 1900014). In brief, a thermoelectrically cooled IR5 MCT detector (IR5) (Polymer Char, Spain) is connected to the GPC column via a heat transfer line. Chromatographic data are obtained from the two output ports of the IR5 detector. First, the analog signal was passed from the analog output port to a digitizer via Cirrus software (Polymer Labs, now an Agilent Company) and an integral calibration method using broad HDPE MARLEX BHB5003 resin (Chevron Phillips Chemical) as a broad molecular weight standard before being connected to computer "A" for molecular weight determination. In another aspect, the digital signal was passed directly to computer "B" via a USB cable where it was collected by LabView data collection software provided by Polymer Char. The chromatographic conditions were set as follows: column oven temperature was 145°C; flow rate was 1 mL / min; injection volume was 0.4 mL; and polymer concentration was approximately 2 mg / mL, depending on sample molecular weight. The temperature of the thermal transfer line and the IR5 detector sample cell were both set to 150°C, while the temperature of the IR5 detector electronics was set to 60°C. Short chain branching content was determined by an in-house method using CH3(I CH3 ) and CH2(I CH2 ) intensity ratio is determined by combining the calibration curve. The calibration curve is the SCB content (x SCB ) as I CH3 / I CH2To obtain the calibration curve, a set of polyethylene resins (no less than 5) with SCB levels ranging from 0 to about 32 SCB / 1,000 total carbons (SCB standards) were used. All of these SCB standards had known SCB levels and flat SCBD curves that were predetermined by NMR and solvent gradient fractionation-NMR (SGF-NMR) methods, respectively. Using the SCB calibration curve thus established, a curve of the short chain branch distribution across the molecular weight distribution was obtained for resins fractionated by the IR5-GPC system under exactly the same chromatographic conditions as these SCB standards. Using the predetermined SCB calibration curve (i.e., I CH3 / I CH2 The relationship between intensity ratio and elution volume was converted into SCB distribution as a function of MWD by using the MW calibration curve (i.e., the relationship between intensity ratio and SCB content) and the MW calibration curve (i.e., the relationship between molecular weight and elution time), so that I CH3 / I CH2 The intensity ratio and elution time of the ethylene polymer (or base resin) are converted to SCB content and molecular weight. Although not tested, it is expected that the number of short chain branches (SCB) per 1000 total carbon atoms of the ethylene polymer (or base resin) is greater at Mw (or Mz) than at Mn.

[0116] Metal content (such as the amount of catalyst residue in an ethylene polymer or article) can be determined by ICP analysis on a PerkinElmer Optima 8300 instrument. Polymer samples can be ashed with sulfuric acid overnight in a Thermolyne furnace and then acid digested with HCl and HNO3 (3:1 v:v) in a HotBlock.

[0117] Examples 1-17

[0118] Figure 1 The bimodal molecular weight distribution (amount of polymer versus logarithm of molecular weight) of the polymers of Examples 1-6 is shown. Figure 2 The bimodal molecular weight distribution of the polymers of Examples 7-12 is shown, Figure 3 Broad molecular weight distributions are shown for the polymers of Examples 13-17, Table I summarizes the polymer HLMI and certain molecular weight properties for the polymers of Examples 1-17, and Table II summarizes certain rheological properties at 190°C for the polymers of Examples 1-12.

[0119] Example 13 is the base resin for Examples 14-17 (no peroxide) and is a broad ethylene copolymer resin (Chevron-Phillips Chemical Company LP) having a nominal 9 HLMI and a density of 0.95. Base Resin Example 1 (for Examples 1-6; nominal 8-12 HLMI and 0.955-0.96 density) and Base Resin Example 7 (for Examples 7-12; nominal 4.5-6.5 HLMI and 0.95-0.955 density) were produced using a dual metallocene catalyst system with an activator-support, as described below.

[0120] The fluorinated silica-coated alumina activator-support used to produce the base resins of Examples 1 and 7 was prepared as follows. Bohemite was obtained from WR Grace & Company under the designation "Alumina A" and had a mass of approximately 300 m 2 / g surface area, a pore volume of about 1.3 mL / g, and an average particle size of about 100 microns. The alumina was first calcined in dry air at about 600°C for about 6 hours, cooled to ambient temperature, and then contacted with isopropyl alcohol containing tetraethyl orthosilicate to equal 25% by weight SiO2. After drying, the silica-coated alumina was calcined at 600°C for 3 hours. Fluoridated silica-coated alumina (7% by weight F) was prepared by impregnating the calcined silica-coated alumina with a solution of ammonium bifluoride in methanol, drying, and then calcining at 600°C in dry air for 3 hours. Thereafter, the fluoridated silica-coated alumina was collected and stored under dry nitrogen and used without exposure to the atmosphere.

[0121] The pilot plant polymerization was carried out in a 30-gallon slurry loop reactor at a production rate of approximately 33 pounds of polymer per hour. The polymerization was carried out in a loop reactor (also referred to as a slurry process) under continuous particle form process conditions by contacting a bismetallocene solution, an organoaluminum solution (triisobutylaluminum, TIBA) and an activator-support (aluminum oxide coated with fluorinated silica) in isobutane in a 1L stirred autoclave with continuous output to the loop reactor. TIBA and the bismetallocene solution were fed as separate streams into a T-shaped pipe upstream of the autoclave where they contacted each other. The activator-support was rinsed with isobutane at a point after the T-shaped pipe so that the organoaluminum / metallocene mixture contacted and flowed together into the autoclave. The isobutane rinse for transporting the activator-support to the autoclave was set at a rate that would result in a residence time of approximately 30 minutes in the autoclave. The total flow from the autoclave then entered the loop reactor.

[0122] The ethylene used was polymer-grade ethylene obtained from AirGas that was purified by passing through an alumina-zeolite adsorbent column (activated at 230-290° C. in nitrogen). Polymer-grade 1-hexene (obtained from Chevron Phillips Chemical Company) was purified by distillation and passed through an alumina-zeolite adsorbent column activated in nitrogen at 230-290° C. The loop reactor was liquid-filled, had a diameter of 15.2 cm, and a volume of 30 gallons (113.6 liters). Liquid isobutane was used as the diluent. Hydrogen was added at approximately 0.001-0.004 lb / hr to adjust the molecular weight and / or HLMI of the polymer product. The isobutane was polymer-grade isobutane (obtained from Enterprise) that was further purified by distillation and then passed through an alumina column (activated at 230-290° C. in nitrogen). The cocatalyst TIBA was obtained as a 10-12 wt % solution in hydrocarbon and was further diluted to 2 wt % in isobutane. The cocatalyst was added at a concentration in the range of 125 ppm based on the weight of the diluent in the polymerization reactor.

[0123] The reactor conditions included a reactor pressure of about 590 psig, an ethylene mole % of 11-13% (based on isobutane diluent), and a polymerization temperature of 93-100° C. The reactor was operated to have a residence time of about 0.8-1.3 hr. The metallocene concentration in the reactor was in the range of about 1.5 to 2.5 parts per million (ppm) based on the weight of the diluent. The activator-support (fluorinated silica-coated alumina) was fed into the reactor at a rate of about 0.015-0.03 lb / hr. The polymer was removed from the reactor at a rate of about 33 lb / hr and passed through a flash chamber and a purge column. Nitrogen was fed to the purge column to ensure that the fluff was free of hydrocarbons. The structures of MET 1 and MET 2 used in Examples 1 and 7 are as follows:

[0124]

[0125] For Example 1, the MET2:MET1 ratio was 0.67, lb hydrogen / 1000 lb ethylene was 0.063, and lb 1-hexene / lb ethylene was 1.14, while for Example 7, the MET2:MET1 ratio was 0.63, lb hydrogen / 1000 lb ethylene was 0.031, and lb 1-hexene / lb ethylene was 1.14.

[0126] The ethylene polymers of Examples 2-6, 8-12, and 14-17 were prepared by blending the corresponding base resins of Examples 1, 7, and 13 with a masterbatch containing a polymer carrier resin and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane. The amount of peroxide groups ranged from 10 to 300 ppm by weight of peroxide groups based on the weight of the base resin, as shown in Tables I and II. The blends of the base resin and the peroxide masterbatch were compounded using a twin-screw extrusion system (ZSK-300) and then pelletized to form the ethylene polymers of Examples 2-6, 8-12, and 14-17.

[0127] Certain properties of the polymers of Examples 1-17 are summarized in Tables I and II. Many of the peroxide-treated polymers have HLMI values less than 12 g / 10 min, Mw values between 200,000 and 550,000 g / mol, Mn values between 18,000 and 48,000 g / mol, CY-a parameters less than 0.12, and a 0.1 sec -1 Tanδ, 0.5 to 0.75 degrees in 100sec -1 tanδ under 1.3×10 6 to 1×10 7 Pa-sec in 0.001sec -1 In general, as the amount of peroxide increases, the zero shear viscosity, relaxation time and -1 The viscosity increases under the CY-a parameter and at 0.1sec -1 The tanδ under the condition of ΔH decreases.

[0128] Figure 4 The rheological differences between Examples 2-6 and the baseline (no peroxide) of Example 1 are shown. Figure 5 The rheological differences between Examples 8-12 and the baseline (no peroxide) of Example 7 are shown, and Figure 6 The rheological differences between Examples 14-17 and the baseline of Example 13 (no peroxide) are shown. Figure 6 The expected effect of peroxide treatment on viscosity is demonstrated, specifically a steady increase in viscosity in the low shear region as peroxide addition increases. Figure 4-5 The effect of peroxide treatment shown in is unexpected and, while not wishing to be bound by theory, may be a result of different amounts of chain scission and crosslinking in the very high molecular weight fraction of the polymer - also note that Figure 1-2 The surprising change in the shape of the MWD curve at the high molecular weight end (e.g., Log M from about 5.5 to 7) is evident in the Figure 2A.

[0129] Blow molding evaluations for Examples 1-6 were performed on a Sterling blow molding machine having the following specifications. These specific equipment and processing conditions were chosen because the blow molding performance and characteristics thus obtained are typically representative of those obtained from larger commercial-scale blow molding operations. The extruder screw had a 3" diameter, a 24:1 L / D ratio, and a 75HP DC drive motor with a maximum plasticizing capacity of approximately 350 lb of polyethylene / hr. The extruder was equipped with a dynicso pressure indicator, four heating zones with air cooling, and a smooth bore barrel with liquid cooling in the feed zone.

[0130] The maximum shot capacity of the accumulator head (FIFO design) is 10 lb, and the maximum and minimum mold bushing diameters are 8" and 1", respectively. 1 / 2" convergent, and 4" to 8" divergent. The blow molding machine is also equipped with a 100-point MACO program device.

[0131] For Examples 1-6, all extruders and head zones were set at 390°F. The mold was a 9-gallon bottle (Fremont Plastic Mold, 42" circumference), and a 4.5" diverging die with a 30-degree landing angle was used. A constant ejection speed was used. The mold temperature was 50-60°F. The timer was set to 0.5 sec blow delay, 0 sec pre-blow, and 0.25 sec clamp close delay. The air pressure was approximately 90 psig. The minimum wall thickness of the part was in the 45-50 mil range, and the die gap was 0.196". Parts were produced at an extruder speed of 30 RPM and a blow time of 90 sec.

[0132] The weight of the product produced was recorded (Part Weight) and the width of the flashing at the bottom of the product (Flat Bottom) was measured. The re-swell of the polymer can be quantified by the Part Weight (Grams) and the Die Swell of the polymer can be quantified by the Flat Bottom (Inches). The melt strength of the polymers was compared by the Hang Time test using a 0.089" die gap and a 20 RPM extruder speed. The parison was extruded and allowed to hang; when the parison was hung, the extruder speed was reduced to zero. The time from the end of injection to the time the parison left the bushing was recorded as the Hang Time.

[0133] The blow molding evaluation of Example 7-12 is carried out on a Kautex KB-25 blow molding machine with the following specifications. Selecting these specific equipment and processing conditions is because the blow molding performance and characteristics obtained in this way typically represent those obtained from larger commercial-scale blow molding operations. The extruder screw diameter is 80mm, and the L / D ratio is 20:1, and the drive motor is a 60HP DC driver, and the maximum plasticizing capacity is about 330lb polyethylene / hr. The extruder is equipped with a dynicso pressure indicator, three heating zones with air cooling, and a slotted liner for processing the liquid cooling of high molecular weight polyethylene pellets and powdered resin in the feed zone.

[0134] The maximum injection capacity of the accumulator head (FIFO design) is 8.5 lb, and the maximum and minimum mold bushing diameters are 8" and 2", respectively. 1 / 2" converges, and 4" to 8" diverges. The blow molding machine is also equipped with a 100-point Hunkar program device.

[0135] For Examples 7-12, all extruders and die zones were set at 405°F. The mold was a 9-gallon bottle (Fremont Plastic Mold), and a 4.5" diverging die with a 30-degree landing angle was used. Constant extrusion pressure was used. The mold temperature was 50-60°F. The timer was set to 0.5 sec blow delay, 0 sec pre-blow, and 0 sec mold close delay. The air pressure was 90 psig. The minimum wall thickness of the part was in the 45-50 mil range, and the die gap was 0.196". The parts were produced at an extruder speed of 30 RPM and a blow time of 90 sec.

[0136] The weight of the product produced was recorded (Part Weight) and the width of the flashing at the bottom of the product (Flat Bottom) was measured. The weight swell of the polymer can be quantified by the Part Weight (Grams) and the die swell of the polymer can be quantified by the Flat Bottom (Inches). The melt strength of the polymers was compared by the Hang Time test using a 0.089" die gap and a 20 RPM extruder speed. The parison was extruded and allowed to hang. The time from the end of the injection until the parison left the bushing was recorded as the Hang Time.

[0137] Table III summarizes the blow molding properties of the polymers of Examples 1-12. Figure 7 The die swell and reswell characteristics of Examples 2-6 compared to Example 1 (no peroxide) are shown, and Figure 8Shown are die swell and the re-expansion characteristics of embodiment 8-12 compared with embodiment 7 (without peroxide).Unexpectedly, table and figure have demonstrated the decoupling of die swell and re-expansion.Especially, the die swell (quantified by flat bottom) of embodiment 2-6 compared with embodiment 1 is actually identical, and the die swell of embodiment 8-12 compared with embodiment 7 is actually identical, and re-expansion (quantified by part weight) increases surprisingly with the increase of peroxide load.Therefore, when respectively compared with embodiment 1 and embodiment 7 that are not carried out peroxide treatment, the ratio of part weight (gram) to flat bottom (inch) of embodiment 5-6 and embodiment 11-12 is much larger.Additionally and advantageously, peroxide treatment increases the melt strength of polymer, as reflected by the increase of die hanging time along with the increase of peroxide addition.

[0138]

[0139]

[0140]

[0141] The present invention has been described above with reference to a number of aspects and specific embodiments. A person skilled in the art will appreciate many variations based on the foregoing specific embodiments. All such obvious variations are within the full intended scope of the appended claims. Other aspects of the present invention may include, but are not limited to, the following aspects (aspects are described as "comprising," but may alternatively be "consisting essentially of" or "consisting of"):

[0142] Aspect 1. An ethylene polymer having (or characterized by):

[0143] High load melt index less than or equal to 12 g / 10 min;

[0144] a weight average molecular weight in the range of 200,000 to 550,000 g / mol;

[0145] a number average molecular weight ranging from 18,000 to 48,000 g / mol;

[0146] CY-a parameter less than or equal to 0.12;

[0147] In the range of 0.5 to 0.9 degrees in 0.1 sec -1 tanδ under

[0148] In the range of 0.5 to 0.75 degrees in 100 seconds -1 tanδ under ; and

[0149] In 1.3×10 6to 1×10 7 Within 0.001sec in the Pa-sec range -1 The viscosity below.

[0150] Aspect 2. A polymer as defined in aspect 1, wherein the HLMI of the ethylene polymer is within any range disclosed herein, for example, less than or equal to 10, less than or equal to 8, 1 to 12, 1 to 10, 1 to 8, 2 to 12, 2 to 10 g / 10 min, etc.

[0151] Aspect 3. A polymer as defined in aspect 1 or 2, wherein the Mw of the ethylene polymer is in any range disclosed herein, for example, 200,000 to 500,000 g / mol, 250,000 to 550,000 g / mol, 250,000 to 500,000 g / mol, 250,000 to 475,000 g / mol, 275,000 to 550,000 g / mol, 275,000 to 475,000 g / mol, etc.

[0152] Aspect 4. A polymer as defined in any of the preceding aspects, wherein the CY-a parameter of the ethylene polymer is within any range disclosed herein, for example, less than or equal to 0.11, less than or equal to 0.1, less than or equal to 0.08, less than or equal to 0.06, 0.01 to 0.12, 0.01 to 0.1, 0.01 to 0.08, 0.01 to 0.06, etc.

[0153] Aspect 5. A polymer as defined in any one of the preceding aspects, wherein the ethylene polymer has a 0.1 sec -1 The tan delta at t is within any range disclosed herein, e.g., 0.5 to 0.85 degrees, 0.5 to 0.8 degrees, 0.55 to 0.9 degrees, 0.55 to 0.85 degrees, 0.6 to 0.9 degrees, 0.6 to 0.85 degrees, 0.6 to 0.8 degrees, etc.

[0154] Aspect 6. A polymer as defined in any one of the preceding aspects, wherein the ethylene polymer has a -1 The tan delta at t is within any range disclosed herein, e.g., 0.5 to 0.72 degrees, 0.5 to 0.7 degrees, 0.52 to 0.75 degrees, 0.52 to 0.72 degrees, 0.52 to 0.7 degrees, 0.55 to 0.75 degrees, 0.55 to 0.72 degrees, etc.

[0155] Aspect 7. A polymer as defined in any one of the preceding aspects, wherein the ethylene polymer has a molecular weight of 0.001 sec -1 The viscosity is within any range disclosed herein, for example, 1.3×10 6 to 5.5×106 Pa-sec, 1.3×10 6 to 5×10 6 Pa-sec, 1.5×10 6 to 1×10 7 Pa-sec, 1.5×10 6 to 6×10 6 Pa-sec, 1.5×10 6 to 5×10 6 Pa-sec, 2×10 6 to 6×10 6 Pa-sec, 2×10 6 to 5×10 6 Pa-sec et al.

[0156] Aspect 8. A polymer as defined in any one of the preceding aspects, wherein the ethylene polymer has a -1 The viscosity at the lower limit is within any range disclosed herein, for example, 1700 to 3300 Pa-sec, 1800 to 3200 Pa-sec, 1900 to 3100 Pa-sec, 2000 to 3000 Pa-sec, etc.

[0157] Aspect 9. A polymer as defined in any of the preceding aspects, wherein the zero shear viscosity of the ethylene polymer is within any range disclosed herein, for example 1×10 8 to 1×10 30 Pa-sec, 1×10 8 to 1×10 28 Pa-sec, 1×10 10 to 1×10 30 Pa-sec, 1×10 10 to 1×10 27 Pa-sec, 1×10 12 to 1×10 27 Pa-sec et al.

[0158] Aspect 10. The polymer as defined in any of the preceding aspects, wherein the ethylene polymer has a density within any range disclosed herein, such as 0.935 to 0.965, 0.94 to 0.965, 0.945 to 0.965, 0.94 to 0.96, 0.945 to 0.96 g / cm 3 wait.

[0159] Aspect 11. A polymer as defined in any of the preceding aspects, wherein the ethylene polymer has a reverse comonomer distribution, for example, the number of short chain branches (SCBs) per 1000 total carbon atoms of the polymer is greater at Mw than at Mn, the number of SCBs per 1000 total carbon atoms of the polymer is greater at Mz than at Mw, the number of SCBs per 1000 total carbon atoms of the polymer is greater at Mz than at Mn, and so on.

[0160] Aspect 12. The polymer as defined in any of the preceding aspects, wherein the Mp of the ethylene polymer is within any range disclosed herein, such as 60,000 to 110,000 g / mol, 65,000 to 105,000 g / mol, 70,000 to 100,000 g / mol, etc.

[0161] Aspect 13. A polymer as defined in any of the preceding aspects, wherein the Mn of the ethylene polymer is within any range disclosed herein, e.g., 20,000 to 46,000 g / mol, 22,000 to 46,000 g / mol, 20,000 to 42,000 g / mol, 22,000 to 40,000 g / mol, etc.

[0162] Aspect 14. The polymer as defined in any of the preceding aspects, wherein the Mw / Mn ratio of the ethylene polymer is within any range disclosed herein, such as 6.5 to 20, 7 to 17, 7.5 to 15, 8 to 13, etc.

[0163] Aspect 15. The polymer as defined in any of the preceding aspects, wherein the Mz / Mw ratio of the ethylene polymer is within any range disclosed herein, such as 4 to 9, 4 to 8, 4.5 to 7.5, 5 to 7, etc.

[0164] Aspect 16. A polymer as defined in any one of the preceding aspects, wherein the relaxation time (τ η ) within any range disclosed herein, for example, 5×10 3 to 1×10 25 sec, 6×10 3 to 1×10 23 sec, 1×10 5 to 1×10 25 sec, 1×10 5 to 1×10 23 sec, 1×10 7 to 1×10 23 sec, etc.

[0165] Aspect 17. A polymer as defined in any of the preceding aspects, wherein the ratio of the restrike swell to the die swell (restrike swell: die swell) of the ethylene polymer is within any range disclosed herein, e.g., 200 to 280, 210 to 270, 230 to 280, 230 to 270, etc., and / or the hang time of the ethylene polymer is within any range disclosed herein, e.g., at least 40 sec, at least 50 sec, at least 100 sec, etc.

[0166] Aspect 18. The polymer as defined in any one of the preceding aspects, wherein the ethylene polymer has a bimodal molecular weight distribution.

[0167] Aspect 19. A polymer as defined in any one of the preceding aspects, wherein the ethylene polymer is a single reactor product, eg, not a post-reactor blend of, for example, two polymers having different molecular weight characteristics.

[0168] Aspect 20. The polymer as defined in any one of the preceding aspects, wherein the ethylene polymer comprises an ethylene / α-olefin copolymer.

[0169] Aspect 21. The polymer of any of the preceding aspects, 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.

[0170] Aspect 22. The polymer as defined in any one of the preceding aspects, wherein the ethylene polymer comprises an ethylene / 1-hexene copolymer.

[0171] Aspect 23. The polymer of any of the preceding aspects, wherein the ethylene polymer independently contains less than 0.1 ppm (by weight), less than 0.08 ppm, less than 0.05 ppm, less than 0.03 ppm, etc., of Mg, V, Ti, or Cr.

[0172] Aspect 24. The polymer of any of the preceding aspects, wherein the ethylene polymer further comprises at least one additive selected from antioxidants, acid scavengers, anti-blocking additives, slip additives, colorants, fillers, processing aids, UV inhibitors, the like, or any combination thereof.

[0173] Aspect 25. An article (eg, a blow molded product) comprising an ethylene polymer as defined in any one of the preceding aspects.

[0174] Aspect 26. An article comprising an ethylene polymer as defined in any one of aspects 1 to 24, wherein the article is an agricultural film, an automotive 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, an outdoor play equipment, a pipe, a sheet or tape, a toy or a traffic barrier, or the like.

[0175] Aspect 27. A process for preparing an ethylene polymer, comprising contacting a base resin with a peroxide compound to produce an ethylene polymer as defined in any one of aspects 1 to 24.

[0176] Aspect 28. The method of aspect 27, wherein the base resin is contacted with 10 to 500 ppm, 25 to 400 ppm, 50 to 350 ppm, etc., of peroxide groups based on the weight of the base resin.

[0177] Aspect 29. The method as defined in Aspect 27 or 28, wherein the contacting step comprises melt processing the blend (or mixture) of the base resin and the peroxide compound at any melt processing temperature disclosed herein (e.g., in the range of 120 to 300° C., in the range of 150 to 250° C., in the range of 175 to 225° C., etc.).

[0178] Aspect 30. The method as defined in aspect 29, wherein the melt processing is carried out in a twin-screw extrusion system.

[0179] Aspect 31. The method as defined in aspect 29, wherein the melt processing is carried out in a single screw extrusion system.

[0180] Aspect 32. A method as defined in any one of Aspects 27-31, wherein the peroxide compound comprises any suitable peroxide compound or any peroxide compound disclosed herein, such as 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, dicumyl peroxide, tert-butylcumyl peroxide, n-butyl-4,4'-di(tert-butylperoxy)valerate, etc., or any combination thereof.

[0181] Aspect 33. The method as defined in any one of aspects 27 to 32, wherein the base resin has (or is characterized by):

[0182] High load melt index in the range of 2 to 40 g / 10 min;

[0183] a weight average molecular weight in the range of 250,000 to 550,000 g / mol;

[0184] CY-a parameter in the range of 0.12 to 0.3;

[0185] In the range of 0.8 to 1.05 degrees in 0.1 sec -1 tanδ under

[0186] In the range of 0.4 to 0.6 degrees in 100 sec -1 tanδ under ; and

[0187] In 1×10 5 to 3×10 6 Within 0.001sec in the Pa-sec range -1 The viscosity below.

[0188] Aspect 34. The method as defined in aspect 33, wherein the HLMI of the base resin is within any range disclosed herein, e.g., 2 to 20, 2 to 12, 4 to 40, 4 to 20, 4 to 15, 4 to 12 g / 10 min, etc.

[0189] Aspect 35. The method as defined in aspect 33 or 34, wherein the base resin has an Mw within any range disclosed herein, e.g., 250,000 to 500,000 g / mol, 250,000 to 475,000 g / mol, 300,000 to 550,000 g / mol, 300,000 to 500,000 g / mol, etc.

[0190] Aspect 36. The method as defined in any of aspects 33-35, wherein the CY-a parameter of the base resin is within any range disclosed herein, e.g., 0.12 to 0.25, 0.13 to 0.3, 0.13 to 0.25, 0.14 to 0.25, etc.

[0191] Aspect 37. A method as defined in any one of aspects 33-36, wherein the base resin has a -1 The tan delta at t is within any range disclosed herein, for example, 0.5 to 0.85 degrees, 0.8 to 1 degree, 0.83 to 1.05 degrees, 0.83 to 1 degree, 0.85 to 1.05 degrees, 0.85 to 1 degree, etc.

[0192] Aspect 38. A method as defined in any one of aspects 33-37, wherein the base resin is -1 The tan delta at t is within any range disclosed herein, e.g., 0.4 to 0.58 degrees, 0.4 to 0.55 degrees, 0.45 to 0.6 degrees, 0.45 to 0.58 degrees, 0.45 to 0.55 degrees, etc.

[0193] Aspect 39. A method as defined in any one of aspects 33-38, wherein the base resin has a -1 The viscosity is within any range disclosed herein, for example, 1×10 5 to 2×10 6 Pa-sec, 1×10 5 to 1.8×10 6 Pa-sec, 8×10 5 to 3×10 6 Pa-sec, 8×10 5 to 2×10 6 Pa-sec, 8×10 5 to 1.8×10 6 Pa-sec et al.

[0194] Aspect 40. The method as defined in any one of aspects 33 to 39, wherein the zero shear viscosity of the base resin is within any range disclosed herein, for example, 1×10 6 to 1×10 9 Pa-sec, 1×10 6 to 2×10 8 Pa-sec, 4×10 6 to 1×10 9 Pa-sec, 4×10 6 to 2×10 8 Pa-sec et al.

[0195] Aspect 41. The method as defined in any of aspects 33-40, wherein the density of the base resin is within any range disclosed herein, e.g., 0.935 to 0.965, 0.94 to 0.965, 0.945 to 0.965, 0.94 to 0.96, 0.945 to 0.96 g / cm 3 wait.

[0196] Aspect 42. A method as defined in any one of Aspects 33-41, wherein the base resin has a reverse comonomer distribution, for example, the number of short chain branches (SCBs) per 1000 total carbon atoms of the polymer is greater at Mw than at Mn, the number of SCBs per 1000 total carbon atoms of the polymer is greater at Mz than at Mw, the number of SCBs per 1000 total carbon atoms of the polymer is greater at Mz than at Mn, and so on.

[0197] Aspect 43. The method as defined in any of aspects 33-42, wherein the base resin has an Mp within any range disclosed herein, e.g., 60,000 to 110,000 g / mol, 65,000 to 105,000 g / mol, 65,000 to 100,000 g / mol, etc.

[0198] Aspect 44. The method as defined in any of aspects 33-43, wherein the base resin has an Mn within any range disclosed herein, e.g., 18,000 to 48,000 g / mol, 20,000 to 42,000 g / mol, 20,000 to 38,000 g / mol, etc.

[0199] Aspect 45. The method as defined in any of aspects 33-44, wherein the base resin has an Mw / Mn ratio within any range disclosed herein, e.g., 9 to 20, 11 to 19, 12 to 18, 13 to 16, etc.

[0200] Aspect 46. The method as defined in any of aspects 33-45, wherein the base resin has an Mz / Mw ratio within any range disclosed herein, such as 4 to 9, 5 to 8, 5 to 7.5, 6 to 8, etc.

[0201] Aspect 47. The method as defined in any of Aspects 33-46, wherein the ratio of the base resin to the die swell (die swell:die swell) is within any range disclosed herein, e.g., 150 to 225, 180 to 225, 170 to 200, etc.

[0202] Aspect 48. The method as defined in any of aspects 33-47, wherein the base resin has a hanging time within any range disclosed herein, such as 10 to 45 sec, 15 to 45 sec, 20 to 45 sec, etc.

[0203] Aspect 49. The method as defined in any one of aspects 33 to 48, wherein the base resin has a bimodal molecular weight distribution.

[0204] Aspect 50. The method as defined in any one of aspects 33 to 49, wherein the base resin is a single reactor product, eg, not a post-reactor blend of, for example, two polymers having different molecular weight characteristics.

[0205] Aspect 51. The method as defined in any one of aspects 33-50, wherein the base resin comprises an ethylene / α-olefin copolymer.

[0206] Aspect 52. The method as defined in any one of aspects 33 to 51, wherein the base resin comprises an ethylene homopolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, and / or an ethylene / 1-octene copolymer.

[0207] Aspect 53. The method as defined in any one of aspects 33 to 52, wherein the base resin comprises an ethylene / 1-hexene copolymer.

[0208] Aspect 54. The method as defined in any one of aspects 33-53, wherein the base resin independently contains less than 0.1 ppm (by weight), less than 0.08 ppm, less than 0.05 ppm, less than 0.03 ppm, etc., of Mg, V, Ti, or Cr.

[0209] Aspect 55. The method as defined in any one of Aspects 33-54, wherein the base resin further comprises at least one additive selected from antioxidants, acid scavengers, anti-blocking additives, slip additives, colorants, fillers, processing aids, UV inhibitors, the like, or any combination thereof.

Claims

1. An ethylene polymer having: HLMI less than or equal to 12 g / 10 min; Mw in the range of 200,000 to 550,000 g / mol; Mn in the range of 18,000 to 48,000 g / mol; CY-a parameter less than or equal to 0.12; In the range of 0.5 to 0.9 degrees in 0.1 sec -1 tanδ under In the range of 0.5 to 0.75 degrees in 100 seconds -1 tanδ under ; and In 1.3×10 6 to 1×10 7 Within 0.001sec in the Pa-sec range -1 The viscosity below.

2. The polymer of claim 1, wherein: The HLMI is in the range of 1 to 10 g / 10 min; The Mw is in the range of 250,000 to 500,000 g / mol; The Mn is in the range of 22,000 to 46,000 g / mol; The CY-a parameter is in the range of 0.01 to 0.1; In 0.1 sec -1 The tanδ under the condition is in the range of 0.6 to 0.85 degrees; In 100 sec -1 The tan delta under the condition of α is in the range of 0.52 to 0.72 degrees; and In 0.001sec -1 The viscosity is 1.5×10 6 to 6×10 6 within the Pa-sec range.

3. The polymer of claim 2, wherein the ethylene polymer comprises an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, an ethylene / 1-octene copolymer, an ethylene homopolymer, or a combination thereof.

4. The polymer of claim 2, wherein the polymer has a relative humidity of 0.94 to 0.96 g / cm 3 Density within the range.

5. The polymer of claim 1, wherein the polymer has: In 1×10 8 to 1×10 30 Zero shear viscosity (η0) in the Pa-sec range; and In 5×10 3 to 1×10 25 Relaxation time (τ η ).

6. The polymer of claim 1, wherein the polymer comprises an ethylene / α-olefin copolymer.

7. The polymer of claim 6, wherein the polymer independently contains less than 0.1 ppm by weight of Mg, V, Ti, and Cr.

8. The polymer of claim 7, wherein the polymer has: In 1×10 10 to 1×10 27 Zero shear viscosity (η0) in the Pa-sec range; and In 1×10 5 to 1×10 23 Relaxation time (τ η ).

9. The polymer of claim 1, wherein: The polymer comprises an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, an ethylene / 1-octene copolymer, an ethylene homopolymer, or a combination thereof; and The polymer further comprises an additive selected from antioxidants, acid scavengers, anti-blocking additives, slip additives, colorants, fillers, processing aids, UV inhibitors, or any combination thereof.

10. The polymer of claim 9, wherein the polymer has: a 100 sec -1 Viscosity under Mp in the range of 65,000 to 105,000 g / mol.

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