High density polyethylene composition

Abstract

The polyethylene composition has a density of > 0.945 g / cm 3 0.8 to 4.0 g / 10 min, an environmental stress crack resistance ESCR determined by ASTM D1693 in 100% IGEPAL CO-630 under condition A or B of more than 400 hours, and a melt strength of > 3.0 cN.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to high density polyethylene compositions having high melt strength, good impact resistance (Izod), and good environmental stress crack resistance (ESCR). The polyethylene compositions are suitable for extrusion applications. BACKGROUND

[0002] When developing thermoplastic resins suitable for use in the preparation of molded articles, such as rotational molded articles, some of the primary considerations include: the time required for the molding of the part (which includes, for example, the flow of the molten resin within the mold, as well as the rate of sintering and cooling of the resin); impact resistance; and resistance to environmental stress over time (e.g., environmental stress crack resistance).

[0003] While several polyethylene resins suitable for use in the molding of parts have been developed (see, for example, U.S. Patent Application Publication Nos. 2016 / 0229964; 20170267822 and U.S. Patent Nos. 9,181,422; 9,540,505; 9,695,309; 10,519,304; 10,329,412; 10,053,564; 9,758,653; 9,637,628; 9,475,927; 9,221,966; 9,074,082; 8,962,755; 8,022,143), there remains a need for new high density polyethylene resins that exhibit both good impact resistance and environmental resistance properties. SUMMARY

[0004] We have now developed polyethylene compositions having high density and high melt strength, as well as good environmental stress crack resistance and impact resistance properties. The polyethylene compositions are useful in the manufacture of molded articles.

[0005] One embodiment of the present disclosure is a polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight Mw1 of > 200,000 g / mol; and (ii) 95 to 50 wt% of a second ethylene copolymer; wherein the first ethylene copolymer has a higher weight average molecular weight Mw1 than the second ethylene copolymer; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; wherein the polyethylene composition has a density of > 0.945 g / cm3; a melt index I2 of 0.8 to 4.0 g / 10 min; a melt flow ratio I10 / I2 of > 50; a molecular weight distribution Mw / Mn of < 6.5; and a melt strength of > 5 cN. w w 3 21 w n ​​​​​; a Z-average molecular weight Mz of > 250,000 g / mol z ; a Z-average molecular weight distribution Mz / Mw of > 2.5 z / M w ; a long chain branching factor LCBF of > 0.0010; and an environmental stress crack resistance ESCR of greater than 400 hours determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B. Environmental stress crack resistance ESCR determined in IGEPAL CO-630 under conditions A and B.

[0006] One embodiment of the present disclosure is a molded article prepared from a polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight Mw of > 200,000 g / mol w ; and (ii) 95 to 50 wt% of a second ethylene copolymer; wherein the first ethylene copolymer has a higher weight average molecular weight Mw than the second ethylene copolymer w ; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; wherein the polyethylene composition has a density of > 0.945 g / cm 3 ; a melt index I2 of 0.8 to 4.0 g / 10 min; a melt flow ratio I 21 / I2 of > 50; a molecular weight distribution Mw / Mn of < 6.5 w / M n ; a Z-average molecular weight Mz of > 250,000 g / mol z ; a Z-average molecular weight distribution Mz / Mw of > 2.5 z / M w ; a long chain branching factor LCBF of > 0.0010; and an environmental stress crack resistance ESCR of greater than 400 hours determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0007] One embodiment of the present disclosure is an extruded article prepared from a polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight Mw of > 200,000 g / mol w ; and (ii) 95 to 50 wt% of a second ethylene copolymer; wherein the first ethylene copolymer has a higher weight average molecular weight Mw than the second ethylene copolymer w ; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; wherein the polyethylene composition has a density of > 0.945 g / cm 3density of ≥ 0.945 g / cm3; a melt index, I2, of 0.8 to 4.0 g / 10 min; a melt flow ratio, I / I2, of ≥ 50; a molecular weight distribution, Mw / Mn, of < 6.5; a Z-average molecular weight, Mz, of ≥ 250,000 g / mol; a Z-average molecular weight distribution, Mz / Mw, of > 2.5; a long chain branching factor, LCBF, of > 0.0010; and an environmental stress crack resistance, ESCR, of greater than 400 hours as determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B. 21 / I2; a molecular weight distribution, Mw / Mn, of < 6.5 w / M n ; a Z-average molecular weight, Mz, of ≥ 250,000 g / mol z ; a Z-average molecular weight distribution, Mz / Mw, of > 2.5 z / M w ; a long chain branching factor, LCBF, of > 0.0010; and an environmental stress crack resistance, ESCR, of greater than 400 hours as determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0008] One embodiment of the present disclosure is an injection molded article prepared from a polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight, Mw, of > 200,000 g / mol; and (ii) 95 to 50 wt% of a second ethylene copolymer; wherein the first ethylene copolymer has a higher weight average molecular weight, Mw, than the second ethylene copolymer; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; wherein the polyethylene composition has a density of ≥ 0.945 g / cm3; a melt index, I2, of 0.8 to 4.0 g / 10 min; a melt flow ratio, I / I2, of ≥ 50; a molecular weight distribution, Mw / Mn, of < 6.5; a Z-average molecular weight, Mz, of ≥ 250,000 g / mol; a Z-average molecular weight distribution, Mz / Mw, of > 2.5; a long chain branching factor, LCBF, of > 0.0010; and an environmental stress crack resistance, ESCR, of greater than 400 hours as determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B. w / I2; a molecular weight distribution, Mw / Mn, of < 6.5 w / M 3 ; a Z-average molecular weight, Mz, of ≥ 250,000 g / mol 21 ; a Z-average molecular weight distribution, Mz / Mw, of > 2.5 w / M n ; a long chain branching factor, LCBF, of > 0.0010; and an environmental stress crack resistance, ESCR, of greater than 400 hours as determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0009] One embodiment of the present disclosure is a compression molded article prepared from a polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight, Mw, of > 200,000 g / mol; and (ii) 95 to 50 wt% of a second ethylene copolymer; wherein the first ethylene copolymer has a higher weight average molecular weight, Mw, than the second ethylene copolymer; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; wherein the polyethylene composition has a density of ≥ 0.945 g / cm3; a melt index, I2, of 0.8 to 4.0 g / 10 min; a melt flow ratio, I / I2, of ≥ 50; a molecular weight distribution, Mw / Mn, of < 6.5; a Z-average molecular weight, Mz, of ≥ 250,000 g / mol; a Z-average molecular weight distribution, Mz / Mw, of > 2.5; a long chain branching factor, LCBF, of > 0.0010; and an environmental stress crack resistance, ESCR, of greater than 400 hours as determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B. z / I2; a molecular weight distribution, Mw / Mn, of < 6.5 z / M w ; a Z-average molecular weight, Mz, of ≥ 250,000 g / mol w ; a Z-average molecular weight distribution, Mz / Mw, of > 2.5 w / M; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; wherein the polyethylene composition has a density of > 0.945 g / cm 3 ; a melt index I2 of 0.8 to 4.0 g / 10 min; a melt flow ratio I 21 / I2 of > 50; a molecular weight distribution M w / M n of < 6.5; a Z-average molecular weight M z of > 250,000 g / mol; a Z-average molecular weight distribution Mz / M w of > 2.5; a long chain branching factor LCBF of > 0.0010; and an environmental stress crack resistance ESCR of more than 400 hours determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0010] One embodiment of the present disclosure is a cap or closure made from a polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight M w of > 200,000 g / mol; and (ii) 95 to 50 wt% of a second ethylene copolymer; wherein the first ethylene copolymer has a weight average molecular weight M w that is higher than the weight average molecular weight M 3 of the second ethylene copolymer; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; wherein the polyethylene composition has a density of > 0.945 g / cm 21 ; a melt index I2 of 0.8 to 4.0 g / 10 min; a melt flow ratio I w / I2 of > 50; a molecular weight distribution M n / M z of < 6.5; a Z-average molecular weight M z of > 250,000 g / mol; a Z-average molecular weight distribution Mz / M w of > 2.5; a long chain branching factor LCBF of > 0.0010; and an environmental stress crack resistance ESCR of more than 400 hours determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0011] One embodiment of the present disclosure is a polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight M w(ii) a first ethylene copolymer; and (ii) 95 to 50% by weight of a second ethylene copolymer; wherein the first ethylene copolymer has a higher weight-average molecular weight M than the second ethylene copolymer. w The first ethylene copolymer has a higher number of short-chain branches per 1000 carbon atoms (SCB1) than the second ethylene copolymer (SCB2); the polyethylene composition has a content of ≥0.945 g / cm³. 3 Density; melt index I2 of 0.8 to 4.0 g / 10 min; melt flow ratio I of ≥50 21 / I2; Molecular weight distribution M <6.5 w / M n Z-average molecular weight M ≥250,000 g / mol z Z-mean molecular weight distribution M > 2.5 z / M w Long chain branching factor (LCBF) > 0.0010; Compositional distribution width index (CDBI) < 50% 50 >3.0 ft-lb / in cantilever beam impact strength; and >1000 hours of environmental stress cracking resistance (ESCR) determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0012] One embodiment of this disclosure is a polyethylene composition comprising: (i) 5 to 50% by weight of a polyethylene compound having a weight-average molecular weight M of >200,000 g / mol. w (ii) a first ethylene copolymer; and (ii) 95 to 50% by weight of a second ethylene copolymer; wherein the first ethylene copolymer has a higher weight-average molecular weight M than the second ethylene copolymer. w The first ethylene copolymer has a higher number of short-chain branches per 1000 carbon atoms (SCB1) than the second ethylene copolymer (SCB2); the polyethylene composition has a content of ≥0.945 g / cm³. 3 Density; melt index I2 of 0.8 to 4.0 g / 10 min; melt flow ratio I of ≥50 21 / I2; Molecular weight distribution M <6.5 w / M n Z-average molecular weight M ≥250,000 g / mol z Z-mean molecular weight distribution M > 2.5 z / M w Long chain branching factor (LCBF) > 0.0010; Compositional distribution width index (CDBI) > 50% 50>1.5 ft-lb / in cantilever beam impact strength; and >400 hours of environmental stress cracking resistance (ESCR) determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0013] In one embodiment of this disclosure, the polyethylene composition has a long-chain branching factor (LCBF) > 0.0050. Attached Figure Description

[0014] Figure 1 Gel permeation chromatograms (GPC-RI) with refractive index detection are shown for polyethylene compositions prepared according to this disclosure and for various comparative resins.

[0015] Figure 2 Gel permeation chromatograms (GPC-FTIR) with Fourier transform infrared detection are shown for the polyethylene compositions prepared according to this disclosure and for various comparative resins. The comonomer content (y-axis) is given as the number of short-chain branches per 1000 main chain carbons relative to the polymer molecular weight (x-axis).

[0016] Figure 3 Temperature wash fractionation (TREF) curves of polyethylene compositions prepared according to this disclosure and various comparative resins are shown.

[0017] Figure 4 The DMA frequency scan data (viscosity η*vs. frequency ω in radians / second) of the polyethylene composition prepared according to this disclosure and the comparative resin are shown.

[0018] Figure 5 The relationship between two performance parameters (cantilever beam impact strength and flexural secant modulus at 1%) of the polyethylene compositions of this disclosure and the compression-molded sheets made from various comparative resins is shown.

[0019] Figure 6 The relationship between two performance parameters (ESCR condition B, 100% IGEPAL vs. flexural secant modulus at 1%) of the polyethylene compositions of this disclosure and the compression-molded sheets made from various comparative resins is shown. Detailed Implementation

[0020] The term “approximately” as used herein will be understood by those skilled in the art and will vary to some extent depending on the context in which it is used. Where a term is used that is not readily apparent to those skilled in the art, “approximately” will mean at most plus or minus 10% of the particular term, taking into account the context in which it is used.

[0021] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the elements (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims absent further indication herein. No language in the specification should be construed as indicating any non-claimed element as essential.

[0022] The term "monomer" as used herein refers to a small molecule that can chemically react and chemically bond to itself or other monomers to form a polymer.

[0023] The term "alpha-olefin" as used herein is used to describe a monomer having a straight chain hydrocarbon chain containing 3 to 20 carbon atoms, said straight chain hydrocarbon chain having a double bond at one end of the chain; the equivalent term is "straight chain alpha-olefin."

[0024] The term "ethylene homopolymer" or "polyethylene homopolymer" means that the polymer referred to is the product of a polymerization process in which only ethylene is intentionally added or intentionally present as a polymerizable monomer.

[0025] The term "ethylene copolymer" or "polyethylene copolymer" means that the polymer referred to is the product of a polymerization process in which ethylene and one or more than one alpha-olefin are intentionally added or intentionally present as polymerizable monomers.

[0026] The term "unsubstituted" as used herein means that a hydrogen group is bonded to the molecular group following the term unsubstituted. The term "substituted" means that the group following the term has one or more moieties (non-hydrogen groups) that replace one or more hydrogen groups at any position within the group.

[0027] The present disclosure provides a polyethylene composition comprising two components: (i) a first ethylene copolymer; and (ii) a second ethylene copolymer that is different from the first ethylene copolymer.

[0028] In one embodiment of the present disclosure, the polyethylene composition can be used to make an extruded article.

[0029] In one embodiment of the present disclosure, the polyethylene composition can be used to make a compression molded article.

[0030] In an embodiment of the disclosure, the polyethylene composition can be used to manufacture injection molded articles.

[0031] First ethylene copolymer

[0032] In an embodiment of the disclosure, the first ethylene copolymer comprises polymerized ethylene and at least one polymerized alpha-olefin comonomer, wherein the polymerized ethylene is the majority species.

[0033] In an embodiment of the disclosure, the alpha-olefins that can be copolymerized with ethylene to make the first ethylene copolymer can be selected from the group consisting of 1- propene, 1-butene, 1-pentene, 1-hexene, and 1-octene, and mixtures thereof.

[0034] In an embodiment of the disclosure, the first ethylene copolymer is made using a single site catalyst, non-limiting examples of which include phosphinimine catalysts, metallocene catalysts, and constrained geometry catalysts, all of which are well known in the art.

[0035] In an embodiment of the disclosure, the first ethylene copolymer is made using a single site polymerization catalyst.

[0036] In an embodiment of the disclosure, the first ethylene copolymer is made using a single site polymerization catalyst in a solution phase polymerization process.

[0037] In an embodiment of the disclosure, the first ethylene copolymer is made using a single site catalyst having hafnium, Hf, as the active metal center.

[0038] In an embodiment of the disclosure, the first ethylene copolymer is an ethylene / 1-octene copolymer.

[0039] In an embodiment of the disclosure, the first ethylene copolymer is made using a metallocene catalyst.

[0040] In an embodiment of the disclosure, the first ethylene copolymer is made using a bridged metallocene catalyst.

[0041] In an embodiment of the disclosure, the first ethylene copolymer is made using a bridged metallocene catalyst having the formula I:

[0042]

[0043] In formula (I): M is a Group 4 metal selected from titanium, zirconium, or hafnium; G is a Group 14 element selected from carbon, silicon, germanium, tin, or lead; R1is a hydrogen atom, a C 1-20 hydrocarbyl group, a C 1-20 alkoxy group, or a C 6-10aryl oxideradical; R2and R3are independently selected from the group consisting of a hydrogen atom, an unsubstituted C 1-20 hydrocarbyl radical, C 1-20 alkoxy radical, or C 6-10 aryl oxideradical; R4and R5are independently selected from the group consisting of a hydrogen atom, an unsubstituted C 1-20 hydrocarbyl radical, a substituted C 1-20 hydrocarbyl radical, C 1-20 alkoxy radical, or C 6-10 aryl oxideradical; and Q is independently an activatable leaving group ligand.

[0044] In one embodiment, G is carbon.

[0045] In one embodiment, R4and R5are independently aryl.

[0046] In one embodiment, R4and R5are independently phenyl or substituted phenyl.

[0047] In one embodiment, R4and R5are phenyl.

[0048] In one embodiment, R4and R5are independently substituted phenyl.

[0049] In one embodiment, R4and R5are substituted phenyl, wherein the phenyl is substituted with a substituted silyl group.

[0050] In one embodiment, R4and R5are substituted phenyl, wherein the phenyl is substituted with a trialkylsilyl group.

[0051] In one embodiment, R4and R5are substituted phenyl, wherein the phenyl is substituted at the para position with a trialkylsilyl group. In one embodiment, R4and R5are substituted phenyl, wherein the phenyl is substituted at the para position with a trimethylsilyl group. In one embodiment, R4and R5are substituted phenyl, wherein the phenyl is substituted at the para position with a triethylsilyl group.

[0052] In one embodiment, R4and R5are independently alkyl.

[0053] In one embodiment, R4and R5are independently alkenyl.

[0054] In one embodiment, R1is hydrogen.

[0055] In one embodiment, R1is alkyl.

[0056] In one embodiment, R1is aryl.

[0057] In one embodiment, R1is alkenyl.

[0058] In one embodiment, R2and R3are independently a hydrocarbyl group having 1 to 30 carbon atoms.

[0059] In one embodiment, R2and R3are independently an aryl group.

[0060] In one embodiment, R2and R3are independently an alkyl group.

[0061] In one embodiment, R2and R3are independently an alkyl group having 1 to 20 carbon atoms.

[0062] In one embodiment, R2and R3are independently a phenyl or substituted phenyl group.

[0063] In one embodiment, R2and R3are t-butyl groups.

[0064] In one embodiment, R2and R3are hydrogen.

[0065] In one embodiment, M is hafnium, Hf.

[0066] In one embodiment of the disclosure, the first ethylene copolymer is prepared with a bridged metallocene catalyst having formula I:

[0067]

[0068] In formula (I): G is a Group 14 element selected from carbon, silicon, germanium, tin, or lead; R1is a hydrogen atom, a C 1-20 hydrocarbyl group, a C 1-20 alkoxy group, or a C 6-10 aryloxy group; R2and R3are independently selected from a hydrogen atom, a C 1-20 hydrocarbyl group, a C 1-20 alkoxy group, or a C 6-10 aryloxy group; R4and R5are independently selected from a hydrogen atom, an unsubstituted C 1-20 hydrocarbyl group, a substituted C 1-20 hydrocarbyl group, a C 1-20 alkoxy group, or a C 6-10 aryloxy group; and Q is independently an activatable leaving group ligand.

[0069] In the present disclosure, the term "activatable" means that the ligand Q can be cleaved from the metal center M via a protolytic decomposition reaction or extracted from the metal center M by a suitable acidic or electrophilic catalyst activator compound (also referred to as a "cocatalyst" compound) respectively, examples of which are described below. The activatable ligand Q can also be transformed into another ligand that is cleaved or extracted from the metal center M (e.g., a halogen group can be converted to an alkyl group). Without wishing to be bound by any single theory, the protolytic decomposition or extraction reaction generates an active "cationic" metal center that can polymerize olefins.

[0070] In embodiments of the present disclosure, the activatable ligand Q is independently selected from the group consisting of a hydrogen atom; a halogen atom; a C 1-20 hydrocarbyl group, C 1-20 alkoxy group, and C 6-10 aryl or aryloxy group, wherein each of the hydrocarbyl, alkoxy, aryl or aryloxy groups can be unsubstituted or further substituted by one or more halogens or other groups; C 1-8 alkyl; C 1-8 alkoxy; C 6-10 aryl or aryloxy; an amido group or a phosphido group, but wherein Q is not cyclopentadienyl. The two Q ligands can also be linked to each other and form, for example, a substituted or unsubstituted diene ligand (e.g., 1,3-butadiene); or a group containing a delocalized heteroatom, such as an acetate or acetamidate group. In one convenient embodiment of the present disclosure, each Q is independently selected from the group consisting of a halogen atom, C 1-4 alkyl and benzyl. Particularly suitable activatable ligands Q are monoanionic, such as a halogen group (e.g., a chloro group) or a hydrocarbyl group (e.g., a methyl group, a benzyl group).

[0071] In one embodiment of the present disclosure, the single site catalyst used to make the first ethylene copolymer is diphenylmethlyene(cyclopentadienyl)(2,7-di-tert-butylfluorenyl) hafnium dichloride having the following molecular formula:

[0072] [(2,7-tBu2Flu)Ph2C(Cp)HfCl2].

[0073] In one embodiment of the present disclosure, the single site catalyst used to make the first ethylene copolymer is diphenylmethlyene(cyclopentadienyl)(2,7-di-tert-butylfluorenyl) hafnium dimethyl having the following molecular formula:

[0074] [(2,7-tBu2Flu)Ph2C(Cp)HfMe2].

[0075] In addition to the single site catalyst molecule itself, the active single site catalyst system can further comprise one or more of the following: an alkylaluminoxane cocatalyst and an ionic activator. The single site catalyst system can also optionally comprise a hindered phenol.

[0076] Although the exact structure of alkylaluminoxane is uncertain, experts in the field generally agree that it is an oligomer containing repeating units of the general formula:

[0077] (R)2AIO-(Al(R)-O) n -Al(R)2

[0078] where the R groups, which can be the same or different, are linear, branched, or cyclic hydrocarbon groups containing 1 to 20 carbon atoms, and n is 0 to about 50. One non-limiting example of an alkylaluminoxane is methylaluminoxane (or MAO). Where each R group is a methyl group.

[0079] In one embodiment of the disclosure, the R of the alkylaluminoxane is a methyl group and m is 10 to 40.

[0080] In one embodiment of the disclosure, the co-catalyst is modified methylaluminoxane (MMAO).

[0081] It is well known in the art that alkylaluminoxanes can act in a dual role as alkylating agents and activators. Thus, alkylaluminoxane co-catalysts are typically used in combination with activatable ligands such as halogens.

[0082] Typically, ionic activators consist of a cation and a bulky anion; where the latter is essentially non-coordinating. One non-limiting example of an ionic activator is a boron ionic activator which is tetra-coordinated to four ligands bonded to the boron atom. Non-limiting examples of boron ionic activators include the following formulae shown below:

[0083] [R 5 ] + [B(R 7 )4] -

[0084] where B represents a boron atom, R 5 is an aromatic hydrocarbon group (e.g., a triphenylmethyl cation) and each R 7 is independently selected from a phenyl group which is unsubstituted or substituted with 3 to 5 substituents selected from a fluorine atom, a C 1-4 alkyl or alkoxy group which is unsubstituted or substituted with a fluorine atom; and a silyl group of the formula -Si(R 9 )3, where each R 9 is independently selected from a hydrogen atom and a C 1-4 alkyl group, and

[0085] [(R 8 ) t ZH] + [B(R 7 )4] -

[0086] where B is a boron atom, H is a hydrogen atom, Z is a nitrogen or phosphorus atom, t is 2 or 3 and R 8 is selected from a C 1-8 alkyl group, a phenyl group which is unsubstituted or substituted with up to three C 1-4 alkyl groups, or one R 8 together with the nitrogen atom can form an anilinium group, and R7 as defined above.

[0087] In both formulas, R 7 Non-limiting examples of the boron ion activator are tetra(perfluorophenyl)boron salts; non-limiting examples include tetra(perfluorophenyl)boron with anilinium and triphenylmethyl (or triphenylmethylium) anilinium salts, carbonium salts, oxonium salts, phosphonium salts, and sulfonium salts. Additional non-limiting examples of ion activators include: triethylammonium tetra(phenyl)boron, tripropylammonium tetra(phenyl)boron, tri(n-butyl)ammonium tetra(phenyl)boron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o-tolyl)boron, tributylammonium tetra(pentafluorophenyl)boron, tripropylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(m,m-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetra(pentafluorophenyl)boron, tri(n-butyl)ammonium tetra(o-tolyl)boron, N,N-dimethylanilinium tetra(phenyl)boron, N,N-diethylanilinium tetra(phenyl)boron, N,N-diethylanilinium tetra(phenyl) n-butylboron, N,N-2,4,6-pentamethylanilinium tetra(phenyl)boron, di-(isopropyl)ammonium tetra(pentafluorophenyl)boron, dicyclohexylammonium tetra(phenyl)boron, triphenylphosphonium tetra(phenyl)boron, tri(methylphenyl)phosphonium tetra(phenyl)boron, tri(dimethylphenyl)phosphonium tetra(phenyl)boron, tetra(pentafluorophenyl)boronic acid onium, triphenylmethyl tetra(pentafluorophenyl)borate, phen(diazonium) tetra(pentafluorophenyl)borate, tetra(2,3,5,6-tetrafluorophenyl)boronic acid onium, triphenylmethyl tetra(pentafluorophenyl)borate, phen(diazonium) tetra(pentafluorophenyl)borate, tetra(2,3,5,6-tetrafluorophenyl)boronic acid onium, triphenylmethyl tetra(pentafluorophenyl)borate, phen(diazonium) tetra(pentafluorophenyl)borate, tetra(2,3,5,6-tetrafluorophenyl)boronic acid onium, triphenylmethyl tetra(pentafluorophenyl)borate, phen(diazonium) tetra(pentafluorophenyl)borate, tetra(2,3,5,6-tetrafluorophenyl)boronic acid onium, triphenylmethyl tetra(pentafluorophenyl)borate, phen(diazonium) tetra(pentafluorophenyl)borate, tetra(2,3,5,6-tetrafluorophenyl)boronic acid

[0088] Non-limiting examples of hindered phenols include butylated phenolic antioxidants, butylated hydroxytoluene, 2,4-di-tert-butyl-6-ethylphenol, 4,4'-methylenebis(2,6-di-tert- butylphenol), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and octadecyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate.

[0089] To produce an active single-site catalyst system, the amounts and molar ratios of the three or four components: single-site catalyst molecule (e.g., metallocene), alkylaluminoxane, ionic activator, and optional hindered phenol are optimized.

[0090] In one embodiment of the disclosure, the single-site catalyst used to make the first ethylene copolymer produces long chain branching, and the first ethylene copolymer will contain long chain branching, hereinafter "LCB".

[0091] LCB is a well-known structural phenomenon in ethylene copolymers and is well known to those of ordinary skill in the art. Traditionally, there are three methods for LCB analysis, namely nuclear magnetic resonance spectroscopy (NMR), see, e.g., J.C. Randall, J Macromol. Sci., Rev. Macromol. Chem. Phys. 1989, 29, 201; triple detector SEC equipped with DRI, viscometer, and low angle laser light scattering detectors, see, e.g., W.W. Yau and D.R. Hill, Int. J. Polym. Anal. Charact. 1996; 2: 151; and rheology, see, e.g., W.W. Graessley, Acc. Chem. Res. 1977, 10, 332-339. In embodiments of the disclosure, the long chain branches are macromolecular in nature, i.e., long enough to be visible in NMR spectroscopy, triple detector SEC experiments, or rheological experiments.

[0092] In one embodiment of the disclosure, the first ethylene copolymer contains long chain branching characterized by the long chain branching factor LCBF disclosed herein. In embodiments of the disclosure, the upper limit of the LCBF of the first ethylene copolymer can be 0.5000, or 0.4000, or 0.3000 (dimensionless). In embodiments of the disclosure, the lower limit of the LCBF of the first ethylene copolymer can be 0.0010, or 0.0015, or 0.0020, or 0.0050, or 0.0070, or 0.0100, or 0.0500, or 0.1000 (dimensionless).

[0093] In embodiments of the disclosure, the first ethylene copolymer has an LCBF of at least 0.0010, or at least 0.0020, or at least 0.0050, or at least 0.0070, or at least 0.0100.

[0094] The first ethylene copolymer can contain catalyst residues that reflect the chemical composition of the catalyst formulation used to make it. Those skilled in the art will appreciate that catalyst residues are typically quantified by, for example, the parts per million of metal in the first ethylene copolymer (or polyethylene composition; see below), where the metal present originates from the metal in the catalyst formulation used to make it. Non-limiting examples of metal residues that can be present include Group 4 metals titanium, zirconium, and hafnium. In embodiments of the disclosure, the upper limit of ppm of metal in the first ethylene copolymer can be about 3.0 ppm, in other cases about 2.0 ppm, and in still other cases about 1.5 ppm. In embodiments of the disclosure, the lower limit of ppm of metal in the first ethylene copolymer can be about 0.03 ppm, in other cases about 0.09 ppm, and in still other cases about 0.15 ppm.

[0095] In one embodiment of the disclosure, the first ethylene copolymer has from 1 to 50 short chain branches per 1000 carbon atoms (SCB1). In further embodiments, the first ethylene copolymer has from 1 to 25 short chain branches per 1000 carbon atoms (SCB1), or from 1 to 15 short chain branches per 1000 carbon atoms (SCB1), or from 1 to 10 short chain branches per 1000 carbon atoms (SCB1).

[0096] Short chain branching (i.e., short chain branching per 1000 main chain carbon atoms, SCB1) is branching that results from the presence of alpha-olefin comonomers in the ethylene copolymer, and has, for example, two carbon atoms for 1-butene comonomers, or four carbon atoms for 1-hexene comonomers, or six carbon atoms for 1-octene comonomers, and the like.

[0097] In one embodiment of the disclosure, the number of short chain branches per 1000 carbon atoms (SCB1) in the first ethylene copolymer is greater than the number of short chain branches per 1000 carbon atoms (SCB2) in the second ethylene copolymer.

[0098] In one embodiment of the disclosure, the density of the first copolymer is less than the density of the second ethylene copolymer.

[0099] In one embodiment of the disclosure, the first ethylene copolymer has a density of from 0.895 to 0.936 g / cm3, or from 0.900 to 0.930 g / cm3, or from 0.905 to 0.925 g / cm3, or from 0.910 to 0.920 g / cm3. 3density of the first ethylene copolymer is from 0.900 to 0.936 g / cm3, or from 0.900 to 0.932 g / cm3, or from 0.900 to 0.930 g / cm3, or from 0.900 to 0.926 g / cm3. 3 . 3 . 3 . 3 . 3 . 3 . 3 . 3 . 3 . 3 . 3 . .

[0100] In an embodiment of the disclosure, the first ethylene copolymer has a melt index, I2, that is less than the melt index, I2, of the second ethylene copolymer.

[0101] In an embodiment of the disclosure, the first ethylene copolymer has a melt index, I2, of < 5.0 g / 10 min, or < 2.5 g / 10 min, or < 1.0 g / 10 min, or < 0.5 g / 10 min, or < 0.4 g / 10 min.

[0102] In an embodiment of the disclosure, the first ethylene copolymer has a melt index, I2, of from 0.001 to 5.0 g / 10 min, including any narrower range within this range and any value encompassed by these ranges. For example, in an embodiment of the disclosure, the first ethylene copolymer can have a melt index, I2, of from 0.01 to 5.0 g / 10 min, or from 0.01 to 2.5 g / 10 min, or from 0.01 to 2.0 g / 10 min, or from 0.01 to 1.5 g / 10 min, 0.01 to 1.0 g / 10 min, or from 0.01 to 0.5 g / 10 min, or from 0.01 to 0.1 g / 10 min.

[0103] In an embodiment of the disclosure, the first ethylene copolymer has a weight average molecular weight, Mw, of greater than 200,000 g / mol, or greater than 225,000 g / mol, or greater than 250,000 g / mol. w .

[0104] In embodiments of the disclosure, the first ethylene copolymer has a weight average molecular weight M w , including any narrower ranges within the broader ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the first ethylene copolymer has a weight average molecular weight M w .

[0105] In one embodiment of the disclosure, the first ethylene copolymer has a melt flow ratio I 21 / I2of less than 25, or less than 23, or less than 20.

[0106] In embodiments of the disclosure, the first ethylene copolymer has a molecular weight distribution M w / M n The upper limit of the molecular weight distribution M w / M n The lower limit of the molecular weight distribution M w / M n may be about 1.6, or about 1.7, or about 1.8, or about 1.9.

[0107] In embodiments of the disclosure, the first ethylene copolymer has a molecular weight distribution M w / M n of ≤ 3.0, or < 3.0, or ≤ 2.7, or < 2.7, or ≤ 2.5, or < 2.5, or ≤ 2.3, or < 2.3, or ≤ 2.1, or < 2.1, or about 2. In another embodiment of the disclosure, the first ethylene copolymer has a molecular weight distribution M w / M n , including any narrower ranges within the broader ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the first ethylene copolymer has a molecular weight distribution M w / M n .

[0108] In one embodiment of the disclosure, the first ethylene copolymer is provided in a solution phase polymerization process in a single reactor in the preparation of the first ethylene copolymer having a CDBI 50single site catalyst for ethylene copolymers.

[0109] In embodiments of the disclosure, the weight percent (wt%) of the first ethylene copolymer in the polyethylene composition (i.e., the weight percent of the first ethylene copolymer based on the total weight of the first ethylene copolymer and the second ethylene copolymer) can be from about 5 wt% to about 60 wt%, including any narrower ranges within this range and any values encompassed by these ranges. For example, in embodiments of the disclosure, the weight percent (wt%) of the first ethylene copolymer in the polyethylene copolymer composition can be from about 5 wt% to about 50 wt%, or from about 10 wt% to about 40 wt%, or from about 15 wt% to about 40 wt%, or from about 15 wt% to about 35 wt%, or from about 10 wt% to about 35 wt%, or from about 20 wt% to about 30 wt%.

[0110] Second ethylene copolymer

[0111] In one embodiment of the disclosure, the second ethylene copolymer comprises polymerized ethylene and at least one polymerized alpha-olefin comonomer, wherein the polymerized ethylene is the majority species.

[0112] In embodiments of the disclosure, the alpha-olefin that can be copolymerized with ethylene to make the second ethylene copolymer can be selected from the group consisting of 1- propene, 1-butene, 1-pentene, 1-hexene, and 1-octene, and mixtures thereof.

[0113] In one embodiment of the disclosure, the second ethylene copolymer is made using a single site catalyst, non-limiting examples of which include phosphinimine catalysts, metallocene catalysts, and constrained geometry catalysts, all of which are well known in the art.

[0114] In one embodiment of the disclosure, the second ethylene copolymer is made using a single site polymerization catalyst.

[0115] In one embodiment of the disclosure, the second ethylene copolymer is made using a single site polymerization catalyst in a solution phase polymerization process.

[0116] In one embodiment of the disclosure, the second ethylene copolymer is made using a single site catalyst having titanium (Ti) as the active metal center.

[0117] In one embodiment of the disclosure, the second ethylene copolymer is an ethylene / 1-octene copolymer.

[0118] In one embodiment of the disclosure, the second ethylene copolymer is made using a phosphinimine catalyst.

[0119] In one embodiment of the present disclosure, the second ethylene copolymer is prepared with a phosphinimine catalyst having formula II:

[0120] (L A ) a M(PI) b (Q) n (II)

[0121] wherein (L A ) represents a cyclopentadienyl-type ligand; M represents a metal atom selected from Ti, Zr and Hf; PI represents a phosphinimine ligand; Q represents an activatable ligand as already defined above; a is 0 or 1 ; b is 1 or 2; (a+b)=2; n is 1 or 2; and the sum of (a+b+n) equals the valence of the metal M.

[0122] The term "cyclopentadienyl-type" ligand as used herein is meant to include ligands containing at least one five-carbon ring bonded to the metal via an η-5 (or in some cases an η-3) bond. As such, the term "cyclopentadienyl-type" includes, for example, unsubstituted cyclopentadienyl, mono- or polysubstituted cyclopentadienyl, unsubstituted indenyl, mono- or polysubstituted indenyl, unsubstituted fluorenyl, and mono- or polysubstituted fluorenyl. Hydrogenated versions of indenyl and fluorenyl ligands are also contemplated for use in the present disclosure, so long as the five-carbon ring bonded to the metal via an η-5 (or in some cases an η-3) bond remains intact. Substituents of the cyclopentadienyl ligand, indenyl ligand (or hydrogenated versions thereof), and fluorenyl ligand (or hydrogenated versions thereof) can be selected from C 1-30 hydrocarbyl groups (which hydrocarbyl groups can be unsubstituted or further substituted by, for example, halogen and / or hydrocarbyl groups; for example, suitable substituted C 1-30 hydrocarbyl groups are pentafluorobenzyl, such as -CH2C6F5); halogen atoms; C 1-8 alkoxy groups; C 6-10 aryl or aryloxy groups (each of which can be further substituted by, for example, halogen and / or hydrocarbyl groups); unsubstituted or substituted amido groups substituted with up to two C 1-8 alkyl groups; unsubstituted or substituted phosphito groups substituted with up to two C 1-8 alkyl groups; silyl groups of the formula -Si(R')3, where each R' is independently selected from hydrogen, C 1-8 alkyl or alkoxy groups, C 6-10 aryl or aryloxy groups; and germyl groups of the formula -Ge(R')3, where R' is as defined directly above.

[0123] The phosphinimine ligand PI is defined by the following formula:

[0124] (R p )3P=N-

[0125] wherein the Rpgroups are independently selected from: a hydrogen atom; a halogen atom; a C 1-20 a hydrocarbyl group, which is unsubstituted or substituted by one or more halogen atoms; a C 1-8 an alkoxy group; a C 6-10 an aryl group; a C 6-10 an aryloxy group; an amido group; a silyl group of formula -Si(R s )3, wherein the R s groups are independently selected from a hydrogen atom, a C 1-8 alkyl or alkoxy group, a C 6-10 aryl group, a C 6-10 aryloxy group, a germyl group of formula -Ge(R G )3, wherein the R G groups are as defined for R s as defined in this paragraph.

[0126] In one embodiment of the present disclosure, the metal M in the phosphinimine catalyst is titanium, Ti.

[0127] In one embodiment of the present disclosure, the single-site catalyst used to make the second ethylene copolymer is cyclopentadienyl tris(tert-butyl) phosphinimine titanium dichloride, Cp((t-Bu)3PN)TiCl2.

[0128] As already discussed above, in addition to the single-site catalyst molecule itself, the active single-site catalyst system can further comprise one or more of: an alkylaluminoxane cocatalyst and an ionic activator, both of which have been defined above. The single-site catalyst system can also optionally comprise a hindered phenol as already defined above.

[0129] In order to produce the active single-site catalyst system, the amounts and molar ratios of the three or four components: the single-site catalyst molecule (e.g. the phosphinimine single-site catalyst molecule), the alkylaluminoxane, the ionic activator and the optional hindered phenol can be optimized.

[0130] In one embodiment of the present disclosure, the single-site catalyst used to make the second ethylene copolymer does not produce long chain branching, and / or the second copolymer will not contain a measurable amount of long chain branching.

[0131] In one embodiment of the present disclosure, the second ethylene copolymer is made with a multi-site catalyst system, non-limiting examples of which include Ziegler-Natta catalysts and chromium catalysts, both of which are well known in the art.

[0132] In one embodiment of the present disclosure, the second ethylene copolymer is made with a Ziegler-Natta catalyst system.

[0133] In one embodiment of the disclosure, the second ethylene copolymer is prepared with a Ziegler-Natta catalyst system in a solution phase polymerization process.

[0134] Ziegler-Natta catalyst systems are well known to those skilled in the art. The Ziegler-Natta catalyst can be an in-line Ziegler-Natta catalyst system or a batch Ziegler-Natta catalyst system. The term “in-line Ziegler-Natta catalyst system” refers to the continuous synthesis of small amounts of active Ziegler-Natta catalyst system and immediate injection of the catalyst into at least one continuously operated reactor, where the catalyst polymerizes ethylene and one or more optional alpha-olefins to form an ethylene polymer. The term “batch Ziegler-Natta catalyst system” or “batch Ziegler-Natta procatalyst” refers to the synthesis of much larger amounts of catalyst or procatalyst in one or more mixing vessels outside or separate from a continuously operated solution polymerization process. Once prepared, the batch Ziegler-Natta catalyst system or batch Ziegler-Natta procatalyst is transferred to a catalyst storage tank. The term “procatalyst” refers to an inactive catalyst system (inactive for ethylene polymerization); the procatalyst is converted to an active catalyst by the addition of an alkyl aluminum cocatalyst. The procatalyst is pumped from the storage tank to at least one continuously operated reactor as needed, where the active catalyst polymerizes ethylene and one or more optional alpha-olefins to form an ethylene copolymer. The procatalyst can be converted to the active catalyst in the reactor or outside the reactor or en route to the reactor.

[0135] A variety of compounds can be used to synthesize the active Ziegler-Natta catalyst system. Various compounds that can be combined to produce an active Ziegler-Natta catalyst system are described below. Those skilled in the art will appreciate that embodiments in the disclosure are not limited to the specific compounds disclosed.

[0136] The active Ziegler-Natta catalyst system can be formed from a magnesium compound, a chloride compound, a metal compound, an alkyl aluminum cocatalyst, and an alkyl aluminum. As will be appreciated by those skilled in the art, the Ziegler-Natta catalyst system can contain additional components; a non-limiting example of an additional component is an electron donor, such as an amine or an ether.

[0137] A non-limiting example of an active in-line (or batch) Ziegler-Natta catalyst system can be prepared as follows. In a first step, a solution of a magnesium compound is reacted with a solution of a chloride compound to form a magnesium chloride support suspended in solution. Non-limiting examples of magnesium compounds include Mg(R 1 )2; where R 1The R groups can be the same or different linear, branched, or cyclic hydrocarbyl groups containing 1 to 10 carbon atoms. Non-limiting examples of chloride compounds include R 2 Cl; wherein R 2 represents a hydrogen atom, or a linear, branched, or cyclic hydrocarbyl group containing 1 to 10 carbon atoms. In the first step, the solution of magnesium compound can also contain an aluminum alkyl compound. Non-limiting examples of aluminum alkyl compounds include Al(R 3 )3, wherein R 3 The R groups can be the same or different linear, branched, or cyclic hydrocarbyl groups containing 1 to 10 carbon atoms. In the second step, a solution of a metal compound is added to the solution of magnesium chloride, the metal compound being supported on the magnesium chloride. Non-limiting examples of suitable metal compounds include M(X) n or MO(X) n ; wherein M represents a metal selected from Groups 4 to 8 of the Periodic Table of the Elements, or a mixture of metals selected from Groups 4 to 8; O represents oxygen; X represents a chlorine or bromine radical; and n is an integer from 3 to 6 satisfying the oxidation state of the metal. Additional non-limiting examples of suitable metal compounds include Group 4 to 8 metal alkyls, metal alkoxides (which can be prepared by reacting a metal alkyl with an alcohol), and mixed-ligand metal compounds containing a mixture of halogen radicals, alkyl, and alkoxide ligands. In one embodiment of the disclosure, the suitable metal compound is titanium tetrachloride, TiCl4. In the third step, a solution of an aluminum alkyl cocatalyst is added to the metal compound supported on the magnesium chloride. A variety of aluminum alkyl cocatalysts are suitable, such as represented by the following formula:

[0138] Al(R 4 ) p (OR 9 ) q (X) r

[0139] wherein R 4 The R groups can be the same or different linear, branched, or cyclic hydrocarbyl groups containing 1 to 10 carbon atoms. Non-limiting examples of chloride compounds include R 9 The OR groups can be the same or different alkoxyl or aryloxyl radicals, wherein R 9 is a hydrocarbyl radical having 1 to 10 carbon atoms bonded to oxygen; X is a chlorine or bromine radical; and (p+q+r)=3, with the proviso that p is greater than 0. Non-limiting examples of commonly used aluminum alkyl cocatalysts include trimethylaluminum, triethylaluminum, tributylaluminum, dimethyl aluminum methoxide, diethyl aluminum ethoxide, dibutyl aluminum butoxide, dimethyl aluminum chloride or bromide, diethyl aluminum chloride or bromide, dibutyl aluminum chloride or bromide, and ethyl aluminum dichloride or dibromide.

[0140] The process for synthesizing the active in-line (or batch) Ziegler-Natta catalyst system described in the above paragraph can be conducted in various solvents; non-limiting examples of solvents include linear or branched C5to C20hydrocarbons, or mixtures thereof. 12 alkanes or mixtures thereof.

[0141] The second ethylene copolymer can contain catalyst residues that reflect the chemical composition of the catalyst formulation used to make it. Those skilled in the art will appreciate that catalyst residues are typically quantified by, for example, the parts per million of metal in the second ethylene copolymer (or polyethylene composition; see below), where the metal present originates from the metal in the catalyst formulation used to make it. Non-limiting examples of metal residues that can be present include Group 4 metals titanium, zirconium, and hafnium. In embodiments of the present disclosure, the upper limit of ppm of metal in the second ethylene copolymer can be about 3.0 ppm, in other cases about 2.0 ppm, and in still other cases about 1.5 ppm. In embodiments of the present disclosure, the lower limit of ppm of metal in the second ethylene copolymer can be about 0.03 ppm, in other cases about 0.09 ppm, and in still other cases about 0.15 ppm.

[0142] In one embodiment of the present disclosure, the short chain branching in the second ethylene copolymer can be about 0.05 to about 5.0 short chain branches per 1000 carbon atoms (SCB2 / 1000C). In further embodiments of the present disclosure, the short chain branching in the second ethylene copolymer can be 0.10 to 3.0, or 0.10 to 2.5, or 0.10 to 2.0, or 0.10 to 1.5, or 0.10 to 1.0, or 0.10 to 0.50, or 0.05 to 3.0, or 0.05 to 2.5, or 0.05 to 2.0, or 0.05 to 1.5, or 0.05 to 1.0, or 0.05 to 0.50 short chain branches per 1000 carbon atoms (SCB2 / 1000C).

[0143] Short chain branching (i.e., short chain branching per 1000 main chain carbon atoms, SCB2) is branching that results from the presence of alpha-olefin comonomers in the ethylene copolymer, and has, for example, two carbon atoms for 1-butene comonomers, or four carbon atoms for 1-hexene comonomers, or six carbon atoms for 1-octene comonomers, and so on.

[0144] In one embodiment of the present disclosure, the number of short chain branches per 1000 carbon atoms (SCB2) in the second ethylene copolymer is less than the number of short chain branches per 1000 carbon atoms (SCB1) in the first ethylene copolymer.

[0145] In an embodiment of the disclosure, the second copolymer has a density greater than the density of the first ethylene copolymer.

[0146] In an embodiment of the disclosure, the second ethylene copolymer has a density of 0.945 to 0.975 g / cm 3 , including any narrower ranges within the ranges and any values encompassed by the ranges. For example, in an embodiment of the disclosure, the second ethylene copolymer has a density of 0.945 to 0.970 g / cm 3 , or 0.945 to 0.967 g / cm 3 , or 0.950 to 0.970 g / cm 3 , or 0.950 to 0.967 g / cm 3 , or 0.955 to 0.970 g / cm 3 , or 0.955 to 0.967 g / cm 3 , or 0.960 to 0.970 g / cm 3 , or 0.960 to 0.967 g / cm 3 .

[0147] In an embodiment of the disclosure, the second ethylene copolymer has a melt index I2 greater than the melt index I2 of the first ethylene copolymer.

[0148] In an embodiment of the disclosure, the second ethylene copolymer has a melt index I2 of > 10.0 g / 10 min, or > 10.0 g / 10 min, or > 20.0 g / 10 min, or > 20 g / 10 min.

[0149] In an embodiment of the disclosure, the second ethylene copolymer has a melt index I2 of 10 to 1,000 g / 10 min, including any narrower ranges within the ranges and any values encompassed by the ranges. For example, in an embodiment of the disclosure, the second ethylene copolymer has a melt index I2 of 10 to 500 g / 10 min, or 10 to 250 g / 10 min, or 10 to 150 g / 10 min, or 20 to 500 g / 10 min, or 20 to 250 g / 10 min, or 20 to 150 g / 10 min, or 10 to 100 g / 10 min, or 20 to 100 g / 10 min.

[0150] In an embodiment of the disclosure, the second ethylene copolymer has a weight average molecular weight M w of < 75,000 g / mol, or < 60,000 g / mol, or < 50,000 g / mol, or < 45,000 g / mol.

[0151] In embodiments of the disclosure, the second ethylene copolymer has a weight average molecular weight Mw of from 5,000 to 75,000 g / mol w , including any narrower ranges within the ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the second ethylene copolymer has a weight average molecular weight Mw of from 10,000 to 75,000 g / mol, or from 15,000 to 75,000 g / mol, or from 15,000 to 65,000 g / mol, or from 15,000 to 60,000 g / mol, or from 15,000 to 50,000 g / mol, or from 20,000 to 60,000 g / mol, or from 20,000 to 55,000 g / mol, or from 20,000 to 50,000 g / mol, or from 20,000 to 45,000 g / mol w .

[0152] In one embodiment of the disclosure, the second ethylene copolymer has a melt flow ratio I 21 / I2of less than 25, or less than 23, or less than 20.

[0153] In embodiments of the disclosure, the second ethylene copolymer has a molecular weight distribution M w / M n may be about 2.7, or about 2.5, or about 2.4, or about 2.3, or about 2.2. In embodiments of the disclosure, the second ethylene copolymer has a molecular weight distribution M w / M n may be about 1.6, or about 1.7, or about 1.8, or about 1.9.

[0154] In embodiments of the disclosure, the second ethylene copolymer has a molecular weight distribution M w / M n of ≤ 3.0, or < 3.0, or ≤ 2.7, or < 2.7, or ≤ 2.5, or < 2.5, or ≤ 2.3, or < 2.3, or ≤ 2.1, or < 2.1, or about 2. In another embodiment of the disclosure, the second ethylene copolymer has a molecular weight distribution M w / M n may be about 2.7, or about 2.5, or about 2.4, or about 2.3, or about 2.2. In embodiments of the disclosure, the second ethylene copolymer has a molecular weight distribution M w / M n .

[0155] In embodiments of the disclosure, the second ethylene copolymer has a molecular weight distribution Mw / Mn of > 2.3, or > 2.3, or > 2.5, or > 2.5, or > 2.7, or > 2.7, or > 2.9, or > 2.9, or > 3.0, or 3.0 w / M n In embodiments of the disclosure, the second ethylene copolymer has a molecular weight distribution Mw / Mn of 2.3 to 6.0, or 2.3 to 5.5, or 2.3 to 5.0, or 2.3 to 4.5, or 2.3 to 4.0, or 2.3 to 3.5, or 2.3 to 3.0, or 2.5 to 5.0, or 2.5 to 4.5, or 2.5 to 4.0, or 2.5 to 3.5, or 2.7 to 5.0, or 2.7 to 4.5, or 2.7 to 4.0, or 2.7 to 3.5. w / M n .

[0156] In one embodiment of the disclosure, a single-site catalyst providing an ethylene copolymer having a CDBI of at least 60 wt%, or at least 65 wt%, or at least 70 wt%, or at least 75 wt%, or at least 80 wt%, or at least 85 wt% in a solution phase polymerization process in a single reactor is used in the preparation of the second ethylene copolymer. 50

[0157] In one embodiment of the disclosure, a multi-site catalyst providing an ethylene copolymer having a CDBI of less than 60 wt%, or less than 50 wt% in a solution phase polymerization process in a single reactor is used in the preparation of the second ethylene copolymer. 5o

[0158] In embodiments of the disclosure, the weight percent (wt%) of the second ethylene copolymer in the polyethylene composition (i.e., the weight percent of the second ethylene copolymer based on the total weight of the first ethylene copolymer and the second ethylene copolymer) can be from about 95 wt% to about 40 wt%, including any narrower ranges within this range and any values encompassed by these ranges. For example, in embodiments of the disclosure, the weight percent (wt%) of the second ethylene copolymer in the polyethylene copolymer composition can be from about 95 wt% to about 50 wt%, or from about 90 wt% to about 40 wt%, or from about 85 wt% to about 50 wt%, or from about 90 wt% to about 60 wt%, or from about 85 wt% to about 60 wt%, or from about 85 wt% to about 65 wt%.

[0159] Polyethylene composition

[0160] In one embodiment of the disclosure, the polyethylene composition will comprise a first ethylene copolymer and a second ethylene copolymer (each as defined above).​​

[0161] The polyethylene composition disclosed herein can be prepared using any technique known in the art, including but not limited to melt blending, solution blending, or in-reactor blending to mix the first ethylene copolymer and the second ethylene copolymer together.

[0162] In one embodiment, the polyethylene composition of the present disclosure is prepared using a single-site catalyst in a first reactor to obtain the first ethylene copolymer and a single-site catalyst in a second reactor to obtain the second ethylene copolymer.

[0163] In one embodiment, the polyethylene composition of the present disclosure is prepared using a single-site catalyst in a first reactor to obtain the first ethylene copolymer and a multi-site catalyst in a second reactor to obtain the second ethylene copolymer.

[0164] In one embodiment, the polyethylene composition of the present disclosure is prepared by forming a first ethylene copolymer by polymerizing ethylene and an alpha-olefin in a first reactor with a single-site catalyst; and forming a second ethylene copolymer by polymerizing ethylene and an alpha-olefin in a second reactor with a single-site catalyst.

[0165] In one embodiment, the polyethylene composition of the present disclosure is prepared by forming a first ethylene copolymer by polymerizing ethylene and an alpha-olefin in a first reactor with a single-site catalyst; and forming a second ethylene copolymer by polymerizing ethylene and an alpha-olefin in a second reactor with a multi-site catalyst.

[0166] In one embodiment, the polyethylene composition of the present disclosure is prepared by forming a first ethylene copolymer by polymerizing ethylene and an alpha-olefin in a first solution phase polymerization reactor with a single-site catalyst; and forming a second ethylene copolymer by polymerizing ethylene and an alpha-olefin in a second solution phase polymerization reactor with a single-site catalyst.

[0167] In one embodiment, the polyethylene composition of the present disclosure is prepared by forming a first ethylene copolymer by polymerizing ethylene and an alpha-olefin in a first solution phase polymerization reactor with a single-site catalyst; and forming a second ethylene copolymer by polymerizing ethylene and an alpha-olefin in a second solution phase polymerization reactor with a multi-site catalyst.

[0168] In an embodiment, the polyethylene composition of the present disclosure is prepared by a process comprising: forming a first ethylene copolymer by polymerizing ethylene and alpha-olefins in a first solution phase polymerization reactor with a single site catalyst; and forming a second ethylene copolymer by polymerizing ethylene and alpha-olefins in a second solution phase polymerization reactor with a single site catalyst, wherein the first and second solution phase polymerization reactors are configured in series with each other.

[0169] In an embodiment, the polyethylene composition of the present disclosure is prepared by a process comprising: forming a first ethylene copolymer by polymerizing ethylene and alpha-olefins in a first solution phase polymerization reactor with a single site catalyst; and forming a second ethylene copolymer by polymerizing ethylene and alpha-olefins in a second solution phase polymerization reactor with a multi-site catalyst, wherein the first and second solution phase polymerization reactors are configured in series with each other.

[0170] In an embodiment, the polyethylene composition of the present disclosure is prepared by a process comprising: forming a first ethylene copolymer by polymerizing ethylene and alpha-olefins in a first solution phase polymerization reactor with a single site catalyst; and forming a second ethylene copolymer by polymerizing ethylene and alpha-olefins in a second solution phase polymerization reactor with a single site catalyst, wherein the first and second solution phase polymerization reactors are configured in parallel with each other.

[0171] In an embodiment, the polyethylene composition of the present disclosure is prepared by a process comprising: forming a first ethylene copolymer by polymerizing ethylene and alpha-olefins in a first solution phase polymerization reactor with a single site catalyst; and forming a second ethylene copolymer by polymerizing ethylene and alpha-olefins in a second solution phase polymerization reactor with a multi-site catalyst, wherein the first and second solution phase polymerization reactors are configured in parallel with each other.

[0172] In an embodiment, the solution phase polymerization reactor used as the first solution phase reactor is a continuous stirred tank reactor or a tubular reactor.

[0173] In an embodiment, the solution phase polymerization reactor used as the second solution phase reactor is a continuous stirred tank reactor or a tubular reactor.

[0174] In solution polymerization, the monomers are dissolved / dispersed in the solvent prior to being fed to the reactor (or for gaseous monomers, the monomers can be fed to the reactor to dissolve in the reaction mixture). Prior to mixing, the solvent and monomers are typically purified to remove potential catalyst poisons such as water, oxygen, or metal impurities. Feedstock purification follows standard practices in the art, for example, molecular sieves, alumina beds, and oxygen scavenger catalysts are used to purify monomers. The solvent itself (e.g., methylpentane, cyclohexane, hexane, or toluene) is also preferably treated in a similar manner.

[0175] The feedstock can be heated or cooled prior to being fed to the reactor.

[0176] Generally, the catalyst components can be pre-mixed in the solvent used for the reaction or fed into the reactor as separate streams. In some cases, pre-mixing of the catalyst components can be desirable in order to provide reaction time for the catalyst components prior to entering the polymerization reaction zone. Such "in-line mixing" techniques are well known to those skilled in the art.

[0177] Solution polymerization processes for the polymerization or copolymerization of ethylene are well known in the art (see, for example, U.S. Patent Nos. 6,372,864 and 6,777,509). These processes are conducted in the presence of an inert hydrocarbon solvent. In solution phase polymerization reactors, a variety of solvents can be used as the process solvent; non-limiting examples include linear, branched, or cyclic C5to C 12 Alkanes. Suitable catalyst component solvents include aliphatic hydrocarbons and aromatic hydrocarbons. Non-limiting examples of aliphatic catalyst component solvents include linear, branched, or cyclic C5to C 5-12 Aliphatic hydrocarbons, such as pentane, methylpentane, hexane, heptane, octane, cyclohexane, cyclopentane, methylcyclohexane, hydrogenated naphtha, or combinations thereof. Non-limiting examples of aromatic catalyst component solvents include benzene, toluene (methylbenzene), ethylbenzene, o-xylene (1,2-dimethylbenzene), m-xylene (1,3-dimethylbenzene), p-xylene (1,4-dimethylbenzene), mixtures of xylene isomers, mesitylene (1,2,3-trimethylbenzene), pseudocumene (1,2,4-trimethylbenzene), mesitylene (1,3,5-trimethylbenzene), mixtures of trimethylbenzene isomers, prehenitene (1,2,3,4-tetramethylbenzene), durene (1,2,3,5-tetramethylbenzene), mixtures of tetramethylbenzene isomers, pentamethylbenzene, hexamethylbenzene, and combinations thereof.

[0178] In embodiments of the present disclosure, the polymerization temperature in the conventional solution process can be from about 80°C to about 300°C. In one embodiment of the present disclosure, the polymerization temperature in the solution process is from about 120°C to about 250°C.

[0179] In embodiments of the present disclosure, the polymerization pressure in the solution process can be a "medium pressure process," meaning the pressure in the reactor is less than about 6,000 psi (about 42,000 kiloPascals or kPa). In embodiments of the present disclosure, the polymerization pressure in the solution process can be from about 10,000 to about 40,000 kPa, or from about 14,000 to about 22,000 kPa (i.e., from about 2,000 psi to about 3,000 psi).

[0180] In embodiments of the present disclosure, comonomers (i.e., alpha-olefins) suitable for copolymerization with ethylene in a solution phase polymerization process include C 3-20Monoolefins and dienes. In embodiments of this disclosure, the comonomers that can be copolymerized with ethylene include unsubstituted or copolymerized with at most two C atoms. 1-6 C with alkyl group substitution 3-12 α-olefins, unsubstituted or selected from at most two C4 groups. 1-4 Substituents of alkyl groups, C 8-12 Vinyl aromatic monomers, unsubstituted or C 1-4 C with alkyl group substitution 4-12 Linear or cyclic dienes. In further embodiments of this disclosure, the α-olefin that can copolymerize with ethylene is one or more of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene and 1-decene, styrene, α-methylstyrene and constrained-ring cyclic olefins such as cyclobutene, cyclopentene, dicyclopentadiene, norbornene, alkyl-substituted norbornene, alkenyl-substituted norbornene, etc. (e.g., 5-methylene-2-norbornene and 5-ethylidene-2-norbornene, bicyclo-(2,2,1)-hept-2,5-diene).

[0181] In one embodiment of this disclosure, the polyethylene composition comprises ethylene and one or more α-olefins selected from 1-butene, 1-hexene, 1-octene, and mixtures thereof.

[0182] In one embodiment of this disclosure, the polyethylene composition comprises ethylene and one or more α-olefins selected from 1-hexene, 1-octene, and mixtures thereof.

[0183] In one embodiment of this disclosure, the polyethylene composition comprises ethylene and 1-octene.

[0184] In embodiments of this disclosure, the polyethylene composition has 0.01 to 5 mol% of one or more α-olefins, including any narrower range within that range and any values ​​covered by those ranges. For example, in embodiments of this disclosure, the polyethylene composition has 0.05 to 5.0 mol% of one or more α-olefins, or 0.05 to 2.5 mol% of one or more α-olefins, or 0.05 to 1.5 mol% of one or more α-olefins, or 0.05 to 1.0 mol% of one or more α-olefins, or 0.1 to 2.5 mol% of one or more α-olefins, or 0.1 to 1.5 mol% of one or more α-olefins, or 0.1 to 1.0 mol% of one or more α-olefins.

[0185] In embodiments of the disclosure, the polyethylene composition has 0.05 to 5.0 mol% 1-octene, or 0.05 to 2.5 mol% 1-octene, or 0.05 to 1.5 mol% 1-octene, or 0.05 to 1.0 mol% 1-octene, or 0.1 to 2.5 mol% 1-octene, or 0.1 to 1.5 mol% 1-octene, or 0.10 to 1.0 mol% 1-octene.

[0186] In one embodiment of the disclosure, the polyethylene composition comprising a first ethylene copolymer and a second ethylene copolymer (as defined above) will have a ratio of the number of short chain branches per 1000 carbon atoms in the first ethylene copolymer (i.e., SCB1) to the number of short chain branches per 1000 carbon atoms in the second ethylene copolymer (i.e., SCB2) (i.e., SCB1 / SCB2) of at least 5.0 (i.e., SCB1 / SCB2≥ 5.0). In further embodiments of the disclosure, the ratio of the short chain branching in the first ethylene copolymer (SCB1) to the short chain branching in the second ethylene copolymer (SCB2) is at least 7.5 or greater than 7.5. In still further embodiments of the disclosure, the ratio of the short chain branching in the first ethylene copolymer (SCB1) to the short chain branching in the second ethylene copolymer (SCB2) is at least 10.0 or greater than 10.0.

[0187] In embodiments of the disclosure, the polyethylene composition has a weight average molecular weight Mw of 65,000 to 250,000 g / mol w , including any narrower ranges within the ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition has a weight average molecular weight Mw of 75,000 to 200,000 g / mol, or 65,000 to 175,000 g / mol, or 75,000 to 150,000 g / mol, or 65,000 to 150,000 g / mol, or 75,000 to 125,000 g / mol, or 65,000 to 125,000 g / mol, or 85,000 to 125,000 g / mol, or 90,000 to 125,000 g / mol w .

[0188] In an embodiment of the disclosure, the polyethylene composition has a number average molecular weight M n In a further embodiment of the disclosure, the polyethylene composition has a number average molecular weight M n including any narrower ranges within the broader ranges and any values encompassed by the ranges. For example, in an embodiment of the disclosure, the polyethylene composition has a number average molecular weight M n .

[0189] In an embodiment of the disclosure, the polyethylene composition has a Z average molecular weight M z .

[0190] In a further embodiment of the disclosure, the polyethylene composition has a Z average molecular weight Mzof 250,000 to 600,000 g / mol, including any narrower ranges within the broader ranges and any values encompassed by the ranges. For example, in an embodiment of the disclosure, the polyethylene composition has a Z average molecular weight M z .

[0191] In an embodiment of the disclosure, the polyethylene copolymer composition has a bimodal curve (i.e., a bimodal molecular weight distribution) in a gel permeation chromatography (GPC) analysis.

[0192] In an embodiment of the disclosure, the polyethylene copolymer composition has a bimodal curve in a gel permeation chromatogram generated according to the method of ASTM D6474-99.

[0193] The term "monomodal" is defined herein to mean that there will be only one distinct peak or maximum in the GPC curve. In contrast, the use of the term "bimodal" means that there will be a secondary peak or shoulder representing a higher or lower molecular weight component in addition to the first peak (i.e., the molecular weight distribution can be said to have two maxima in the molecular weight distribution curve). Alternatively, the term "bimodal" means that there are two maxima in the molecular weight distribution curve generated according to the method of ASTM D6474-99. The term "multimodal" means that there are two or more maxima, typically more than two maxima, in the molecular weight distribution curve generated according to the method of ASTM D6474-99.

[0194] In embodiments of the disclosure, the polyethylene composition has a molecular weight distribution M w / M n In further embodiments of the disclosure, the polyethylene composition has a molecular weight distribution M w / M n including any narrower ranges within the ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition has a molecular weight distribution M w / M n .

[0195] In embodiments of the disclosure, the polyethylene composition has a Z average molecular weight distribution M z / M w .

[0196] In embodiments of the disclosure, the polyethylene composition has a Z average molecular weight distribution M z / M w, including any narrower ranges within the broader ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition has a Z average molecular weight distribution Mz / Mw of 2.7 to 4.5, or 2.8 to 4.5, or 3.0 to 4.5, or 3.0 to 5.0. z / M w .

[0197] In embodiments of the disclosure, the polyethylene copolymer composition has a density of > 0.945 g / cm3 3 , or > 0.948 g / cm3 3 , or > 0.949 g / cm3 3 , or > 0.950 g / cm3 3 .

[0198] In embodiments of the disclosure, the polyethylene composition has a density of 0.945 to 0.970 g / cm3 3 , including any narrower ranges within the broader ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition has a density of 0.948 to 0.970 g / cm3 3 , or 0.949 to 0.970 g / cm3 3 , or 0.950 to 0.970 g / cm3 3 , or 0.945 to 0.965 g / cm3 3 , or 0.948 to 0.965 g / cm3 3 , or 0.949 to 0.965 g / cm3 3 , or 0.950 to 0.965 g / cm3 3 , or 0.945 to 0.960 g / cm3 3 , or 0.948 to 0.960 g / cm3 3 , or 0.949 to 0.960 g / cm3 3 , or 0.950 to 0.960 g / cm3 3 , or 0.948 to 0.957 g / cm3 3 , or 0.949 to 0.957 g / cm3 3 .

[0199] In embodiments of the disclosure, the polyethylene composition has a melt index, I2, of 0.001 to 5.0 g / 10 min, including any narrower ranges within the range and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition can have a melt index, I2, of 0.01 to 5.0 g / 10 min, or 0.1 to 5.0 g / 10 min, or 0.01 to 4.0 g / 10 min, or 0.1 to 4.0 g / 10 min, 0.01 to 2.5 g / 10 min, or 0.1 to 2.5 g / 10 min, or 0.5 to 5.0 g / 10 min, or 0.8 to 5.0 g / 10 min, or 0.5 to 4.0 g / 10 min, or 0.8 to 4.0 g / 10 min, or 0.8 to 2.5 g / 10 min, or 1.0 to 5.0 g / 10 min, or 1.0 to 4.0 g / 10 min, or 1.0 to 2.5 g / 10 min.

[0200] In embodiments of the disclosure, the polyethylene composition has a high load melt index, I 21 In further embodiments of the disclosure, the polyethylene composition has a high load melt index, I 21 , including any narrower ranges within the range and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition can have a high load melt index, I 21 , of 65 to 160 g / 10 min, or 70 to 160 g / 10 min, or 60 to 150 g / 10 min, or 65 to 150 g / 10 min, or 70 to 150 g / 10 min, or 80 to 150 g / 10 min, or 90 to 150 g / 10 min, or 60 to 130 g / 10 min, or 60 to 120 g / 10 min, or 70 to 130 g / 10 min.

[0201] In embodiments of the disclosure, the polyethylene composition has a melt flow ratio, I 21 / I2, of > 50, or > 50, or > 55, or > 55, or > 60, or > 60. In further embodiments of the disclosure, the polyethylene composition has a melt flow ratio, I 21 / I2, of 50 to 140, including any narrower ranges within the range and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition has a melt flow ratio, I 21 / I2.

[0202] In an embodiment of the disclosure, the polyethylene composition will have a reverse or partially reverse comonomer distribution profile as measured using GPC-FTIR. The distribution is described as "normal" if comonomer incorporation decreases with decreasing molecular weight as measured using GPC-FTIR. The comonomer distribution is described as "flat" or "uniform" if comonomer incorporation is approximately constant with molecular weight as measured using GPC-FTIR. The terms "reverse comonomer distribution" and "partially reverse comonomer distribution" mean that in the GPC-FTIR data obtained on the copolymer, there is one or more higher molecular weight component(s) with higher comonomer incorporation than one or more lower molecular weight component(s). The term "reverse comonomer distribution" is used herein to refer to a comonomer content of various polymer fractions that is not substantially uniform across the molecular weight range of the ethylene copolymer, and with higher molecular weight fractions having proportionally higher comonomer content (i.e. the distribution is described as "reverse" or "reversed" if comonomer incorporation increases with increasing molecular weight). In the case where comonomer incorporation increases with increasing molecular weight and then decreases, the comonomer distribution is still considered "reverse", but can also be described as "partially reverse". A partially reverse comonomer distribution will exhibit a peak or maximum.

[0203] In an embodiment of the disclosure, the polyethylene composition has a reverse comonomer distribution profile as measured using GPC-FTIR.

[0204] In an embodiment of the disclosure, the polyethylene composition has a partially reverse comonomer distribution profile as measured using GPC-FTIR.

[0205] In an embodiment of the disclosure, the polyethylene composition has a CDBI 50 will be greater than 60 wt%, or greater than 70 wt%, or greater than 80 wt%. In an embodiment of the disclosure, the polyethylene composition has a CDBI 50 will be 60 to 98 wt%, or 70 to 90 wt%, or 80 to 90 wt%.

[0206] In an embodiment of the disclosure, the polyethylene composition has a CDBI 50 will be less than 60 wt%, or less than 50 wt%. In an embodiment of the disclosure, the polyethylene composition has a CDBI 50 will be 30 to 55 wt%, or 30 to 50 wt%, or 35 to 55 wt%, or 35 to 50 wt%.

[0207] In embodiments of the disclosure, the upper limit of the parts per million (ppm) of hafnium in the polyethylene composition (ppm of hafnium metal, based on the weight of the polyethylene composition) can be about 3.0 ppm, or about 2.5 ppm, or about 2.4 ppm, or about 2.0 ppm, or about 1.5 ppm, or about 1.0 ppm, or about 0.75 ppm, or about 0.5 ppm. In embodiments of the disclosure, the lower limit of the parts per million (ppm) of hafnium in the polyethylene composition (ppm of hafnium metal, based on the weight of the polyethylene composition) can be about 0.0015 ppm, or about 0.0050 ppm, or about 0.0075 ppm, or about 0.010 ppm, or about 0.015 ppm, or about 0.030 ppm, or about 0.050 ppm, or about 0.075 ppm, or about 0.100 ppm, or about 0.150 ppm, or about 0.175 ppm, or about 0.200 ppm.

[0208] In embodiments of the disclosure, the polyethylene composition has from 0.0015 to 2.4 ppm of hafnium, or from 0.0050 to 2.4 ppm of hafnium, or from 0.0075 to 2.4 ppm of hafnium, or from 0.010 to 2.4 ppm of hafnium, or from 0.015 to 2.4 ppm of hafnium, or from 0.050 to 3.0 ppm of hafnium, or from 0.050 to 2.4 ppm, or from 0.050 to 2.0 ppm, or from 0.050 to 1.5 ppm, or from 0.050 to 1.0 ppm, or from 0.050 to 0.75 ppm, or from 0.075 to 2.4 ppm of hafnium, or from 0.075 to 2.0 ppm of hafnium, or from 0.075 to 1.5 ppm of hafnium, or from 0.075 to 1.0 ppm of hafnium, or from 0.075 to 0.75 ppm of hafnium, or from 0.100 to 2.0 ppm of hafnium, or from 0.100 to 1.5 ppm of hafnium, or from 0.100 to 1.0 ppm of hafnium, or from 0.100 to 0.75 ppm of hafnium.

[0209] In embodiments of the disclosure, the polyethylene composition has at least 0.0015 ppm of hafnium, or at least 0.005 ppm of hafnium, or at least 0.0075 ppm of hafnium, or at least 0.015 ppm of hafnium, or at least 0.030 ppm of hafnium, or at least 0.050 ppm of hafnium, or at least 0.075 ppm of hafnium, or at least 0.100 ppm of hafnium, or at least 0.125 ppm of hafnium, or at least 0.150 ppm of hafnium, or at least 0.175 ppm of hafnium, or at least 0.200 ppm of hafnium, or at least 0.300 ppm of hafnium, or at least 0.350 ppm of hafnium.

[0210] In embodiments of the disclosure, the polyethylene composition has less than 5.0 ppm of titanium (ppm of titanium metal, based on the weight of the polyethylene composition), or less than 4.0 ppm of titanium, or less than 3.0 ppm of titanium, or less than 3.0 ppm of titanium, or less than 2.0 ppm of titanium, or less than 1.0 ppm of titanium, or less than 0.5 ppm of titanium, or less than 0.3 ppm of titanium.

[0211] In embodiments of the disclosure, the polyethylene composition has less than 25.0 ppm of aluminum (ppm of aluminum metal, based on the weight of the polyethylene composition), or less than 20.0 ppm of aluminum, or less than 15.0 ppm of aluminum, or less than 10.0 ppm of aluminum.

[0212] In embodiments of the disclosure, the polyethylene composition has less than 15.0 ppm of magnesium (ppm of magnesium metal, based on the weight of the polyethylene composition), or less than 10.0 ppm of magnesium, or less than 5.0 ppm of magnesium, or less than 1 ppm of magnesium.

[0213] In one embodiment of the disclosure, the polyethylene composition contains long chain branching characterized by a long chain branching factor, LCBF, disclosed herein. In embodiments of the disclosure, the upper limit of the LCBF of the polyethylene composition can be 0.5000, or 0.4000, or 0.3000 (dimensionless). In embodiments of the disclosure, the lower limit of the LCBF of the polyethylene composition can be 0.0010, or 0.0020, or 0.0050, or 0.0100, or 0.0500, or 0.1000 (dimensionless).

[0214] In embodiments of the disclosure, the LCBF of the polyethylene composition is at least 0.0010, or at least 0.0020, or at least 0.0050, or at least 0.0070, or at least 0.0100, or at least 0.0200, or at least 0.0250.

[0215] In embodiments of the disclosure, the LCBF of the polyethylene composition can be > 0.0010, or > 0.0050, or > 0.0100, or > 0.0200 (dimensionless).

[0216] In embodiments of the disclosure, the polyethylene composition can have a LCBF of 0.0010 to 0.5000, or 0.0010 to 0.1000, or 0.0050 to 0.5000, or 0.0050 to 0.1000, or 0.0070 to 0.5000, or 0.0050 to 0.2500, or 0.0070 to 0.2500, or 0.0100 to 0.5000, or 0.0100 to 0.2500, or 0.0050 to 0.1000, or 0.0070 to 0.1000, or 0.0100 to 0.1000.

[0217] In embodiments of the disclosure, the polyethylene composition has a melt strength of at least 2.0 cN, or at least 2.5 cN, or at least 3.0 cN.

[0218] In embodiments of the disclosure, the polyethylene composition or a sheet made from the polyethylene composition has a tensile secant modulus at 1% of at least 900 MPa, or at least 1000 MPa, or at least 1100 MPa, or at least 1200 MPa. In further embodiments of the disclosure, the polyethylene composition has a tensile secant modulus at 1% of 900 to 1600 MPa, including any narrower ranges within this range and any values encompassed by these ranges. For example, in embodiments of the disclosure, the polyethylene composition has a tensile secant modulus at 1% of 1000 to 1500 MPa, or 1000 to 1400 MPa, or 1100 to 1500 MPa, or 1100 to 1400 MPa, or 1200 to 1500 MPa, or 1200 to 1400 MPa.

[0219] In embodiments of the disclosure, the polyethylene composition or a sheet made from the polyethylene composition has a tensile secant modulus at 1% of at least 900 MPa, or at least 1000 MPa, or at least 1100 MPa, or at least 1200 MPa. In further embodiments of the disclosure, the polyethylene composition has a tensile secant modulus at 1% of 900 to 1600 MPa, including any narrower ranges within this range and any values encompassed by these ranges. For example, in embodiments of the disclosure, the polyethylene composition has a tensile secant modulus at 1% of 900 to 1500 MPa, or 1000 to 1500 MPa, or 900 to 1400 MPa, or 1000 to 1400 MPa, or 1100 to 1500 MPa, or 1200 to 1500 MPa, or 1100 to 1400 MPa, or 1200 to 1400 MPa.

[0220] In embodiments of the disclosure, the polyethylene composition or a sheet made from the polyethylene composition has a notched Charpy impact strength of > 1.0 ft. lb / in, or > 1.0 ft. lb / in, or > 1.5 ft. lb / in, or > 1.5 ft. lb / in, or > 2.0 ft. lb / in, or > 2.5 ft. lb / in, or > 3.0 ft. lb / in, or > 3.0 ft. lb / in. In further embodiments of the disclosure, the polyethylene composition has a notched Charpy impact strength of 1.0 to 8 ft. lb / in, including any narrower ranges within this range and any values encompassed by these ranges. For example, in embodiments of the disclosure, the polyethylene composition has a notched Charpy impact strength of 1.5 to 8 ft. lb / in, or 1.5 to 6 ft. lb / in, or 1.5 to 5.5 ft. lb / in.

[0221] In embodiments of the disclosure, the polyethylene composition or a sheet made from the polyethylene composition has an environmental stress crack resistance, ESCR, in 100% IGEPAL CO-630 under Condition A of greater than 400 hours, or greater than 600 hours, or greater than 800 hours, or greater than 1000 hours, or greater than 1100 hours.

[0222] In embodiments of the disclosure, the polyethylene composition or a sheet made from the polyethylene composition has an environmental stress crack resistance, ESCR, in 100% IGEPAL CO-630 under Condition B of greater than 400 hours, or greater than 600 hours, or greater than 800 hours, or greater than 1000 hours, or greater than 1100 hours.

[0223] In embodiments of the disclosure, the polyethylene composition or a sheet made from the polyethylene composition has an environmental stress crack resistance, ESCR, in 100% IGEPAL CO-630 under Condition A and under Condition B of greater than 400 hours, or greater than 600 hours, or greater than 800 hours, or greater than 1000 hours, or greater than 1100 hours.

[0224] In embodiments of the disclosure, the polyethylene composition or a sheet made from the polyethylene composition has an environmental stress crack resistance, ESCR, in 100% IGEPAL CO-630 under Condition A or under Condition B of greater than 400 hours, or greater than 600 hours, or greater than 800 hours, or greater than 1000 hours, or greater than 1100 hours.

[0225] In embodiments of the disclosure, the polyethylene composition has a shear thinning index, SHI, of > 5.0, or > 7.5, or > 10.0, or > 15.0, or > 20.0 (1，100)In embodiments of the disclosure, the polyethylene composition has a shear thinning index SHI of 7.5 to 40 (1，100) including any narrower ranges within the broader ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition has a shear thinning index SHI of 10.0 to 40.0, or 7.5 to 35.0, or 10.0 to 35.0, or 15.0 to 40.0, or 15.0 to 35.0. (1，100) .

[0226] In embodiments of the disclosure, the polyethylene composition has a relative elasticity G’ / G” at 0.05 rad / s of < 0.75, or < 0.70, or < 0.60, or < 0.50. In embodiments of the disclosure, the polyethylene composition has a relative elasticity G’ / G” at 0.05 rad / s of 0.25 to 0.75, including any narrower ranges within the broader ranges and any values encompassed by the ranges. For example, in embodiments of the disclosure, the polyethylene composition has a relative elasticity G’ / G” at 0.05 rad / s of 0.25 to 0.60, or 0.25 to 0.55, or 0.25 to 0.50.

[0227] Additives can be added to the polyethylene composition during the extrusion or compounding step, although other suitable known methods will be apparent to those skilled in the art. Additives can be added as is or as part of a separate polymer component (i.e., not the first ethylene polymer or the second ethylene polymer described above) that is added during the extrusion or compounding step. Suitable additives are known in the art and include, but are not limited to, antioxidants, phosphites and phosphonites, nitrones, anti-acids, UV light stabilizers, UV absorbers, metal deactivators, dyes, fillers and reinforcing agents, nanoscale organic or inorganic materials, antistatic agents, lubricants such as calcium stearate, slip additives such as erucyrimide, and nucleating agents (including nucleators, pigments, or any other chemical that can provide nucleation to the polyethylene composition). Optionally added additives are typically added in amounts of up to 20 weight percent (wt %).

[0228] One or more nucleating agents can be introduced into the polyethylene composition by kneading a polymer mixture, typically in powder or pellet form, with a nucleating agent that can be used alone or in the form of a concentrate containing other additives such as stabilizers, pigments, antistatic agents, UV stabilizers, and fillers. The nucleating agent should be a material that is wetted or absorbed by the polymer, insoluble in the polymer, and has a melting point higher than that of the polymer, and should be uniformly dispersed in the polymer melt in the finest possible form (1 to 10 μm). Compounds known to have nucleating ability for polyolefins include salts of aliphatic monocarboxylic acids or dicarboxylic acids or arylalkyl acids, such as sodium succinate or aluminum phenylacetate; and alkali metal salts or aluminum salts of aromatic or alicyclic carboxylic acids, such as sodium β-naphthoate. Another compound known to have nucleating ability is sodium benzoate. Nucleating effectiveness can be microscopically monitored by observing the degree of reduction in the size of the spherulites formed by microcrystalline aggregation.

[0229] Examples of commercially available nucleating agents that can be added to the polyethylene composition are dibenzyl sorbitol esters (such as those marketed under the trademark Milliken Chemical). 3988 and trademarked by Ciba Specialty Chemicals (Products for sale). Further examples of nucleating agents that can be added to the polyethylene compositions include cyclic organic structures (and their salts, such as disodium bicyclic [2.2.1]heptenedioate) disclosed in U.S. Patent No. 5,981,636; saturated forms of the structures disclosed in U.S. Patent No. 5,981,636 (such as those disclosed in U.S. Patent No. 6,465,551; Zhao et al., belonging to Milliken); salts of certain cyclic dicarboxylic acids having a hexahydrophthalic acid structure (or "HHPA" structure) as disclosed in U.S. Patent No. 6,599,971 (Dotson et al., belonging to Milliken); and phosphate esters, such as those disclosed in U.S. Patent No. 5,342,868 and those sold by Asahi Denka Kogyo under the trade names NA-11 and NA-21, cyclic dicarboxylic acid esters and their salts, such as divalent metal or metalloid salts (especially calcium salts) of the HHPA structure disclosed in U.S. Patent No. 6,599,971. For clarity, the HHPA structure typically comprises a ring structure having six carbon atoms in the ring and two carboxylic acid groups as substituents on adjacent atoms of the ring structure. The other four carbon atoms in the ring can be substituted as disclosed in U.S. Patent No. 6,599,971. One example is 1,2-cyclohexanedicarboxylic acid, calcium salt (CAS Registry No. 491589-22-1). Further examples of nucleating agents that can be added to the polyethylene composition include those disclosed in WO2015042561, WO2015042563, WO2015042562, and WO 2011050042.

[0230] Many of the above nucleating agents can be difficult to mix with the polyethylene composition to be nucleated and it is known to use dispersing aids (e.g. zinc stearate) to mitigate this problem.

[0231] In one embodiment of the disclosure, the nucleating agent is sufficiently dispersed in the polyethylene composition.

[0232] In one embodiment of the disclosure, the amount of nucleating agent used is relatively small (5 to 3000 parts per million by weight (based on the weight of the polyethylene composition)), and therefore one skilled in the art will recognize that care must be taken to ensure that the nucleating agent is sufficiently dispersed. In one embodiment of the disclosure, the nucleating agent is added to the polyethylene composition in a finely divided form (less than 50 microns, especially less than 10 microns) to facilitate mixing. This type of "physical blend" (i.e. a mixture of the nucleating agent in solid form and the resin) is generally preferred over the use of a nucleating agent "masterbatch" (where the term "masterbatch" refers to the practice of first melt mixing the additive (in this case the nucleating agent) with a small amount of polyethylene composition resin, and then melt mixing this "masterbatch" with the remaining bulk of the polyethylene composition resin).

[0233] In one embodiment of the disclosure, the additive (such as a nucleating agent) can be added to the polyethylene composition by means of a "masterbatch", where the term "masterbatch" refers to the practice of first melt mixing the additive (for example the nucleating agent) with a small amount of polyethylene composition, and then melt mixing this "masterbatch" with the remaining bulk of the polyethylene composition.

[0234] In one embodiment of the disclosure, the polyethylene composition further comprises a nucleating agent or a mixture of nucleating agents.

[0235] In one embodiment of the disclosure, the polyethylene composition is used to form molded articles. For example, articles formed by roto-molding, continuous compression molding, and injection molding are contemplated. Such articles include, for example, tanks from roto-molding, and bottle caps, screw caps, and bottle closures from compression or injection molding. However, one skilled in the art will readily recognize that the above compositions can also be used for other applications, such as, but not limited to, film, injection blow molding, blow molding, sheet extrusion, foam injection molding, and foam extruded sheet applications.

[0236] In one embodiment, the polyethylene composition disclosed herein can be converted into a molded article.

[0237] In one embodiment, the polyethylene composition disclosed herein can be converted into an extruded article.

[0238] In one embodiment, the polyethylene composition disclosed herein can be converted into an extrusion coated article.

[0239] In one embodiment, the polyethylene compositions disclosed herein can be converted into roto-molded articles.

[0240] In one embodiment, the polyethylene compositions disclosed herein can be converted into foamed articles.

[0241] In another embodiment, and as an alternative to roto-molding, the polyethylene compositions of the present disclosure can be used to make articles by compression or injection molding processes.

[0242] In one embodiment, the polyethylene compositions disclosed herein can be converted into caps or lids.

[0243] Foamed article

[0244] Polyethylene foams are generally characterized based on their density. Soft or low density polyethylene foams are generally prepared from polyethylene resins that are also characterized as having low density. On the other hand, rigid foams can be used for structural applications. Rigid polyethylene foams, which are characterized as having higher density, generally provide higher tensile and compressive strength compared to lower density polyethylene foams. Foamed polyolefins can provide advantages in the design of molded parts, as they offer the opportunity to reduce the overall part weight as well as to improve thermal and acoustic insulation properties. High pressure low density polyethylene (HPLDPE) is generally used to prepare soft foam articles. Linear low density polyethylene polymers (LLDPE) are also used in various foam applications. The choice of resin, blowing agent, molding equipment, and part design all contribute to the performance of the molded part.

[0245] Known processes for preparing polyolefin foams include sheet extrusion, blown and cast film extrusion, injection molding, roto-molding, and compression molding, and all of these processes are contemplated for use in embodiments of the present disclosure in order to prepare foamed articles using the polyethylene compositions disclosed herein.

[0246] As known to those skilled in the art, blowing agents are used to create foamed polyethylene structures, and blowing agents can be physical or chemical in nature. Physical blowing agents are gases that are typically first dissolved in the polymer melt and then separate upon a change in pressure (decompression) during the foaming process to form the cellular structure. Examples of physical blowing agents include nitrogen, argon, carbon dioxide, fluorocarbons, helium, and hydrocarbons such as butane and pentane. Chemical blowing agents are chemicals that decompose during the foaming operation to produce a gas that in turn forms the cellular structure. Examples of such chemical blowing agents include synthetic azo, carbonate, and hydrazide-based molecules. Typically, the blowing agent decomposes to release a gas, such as nitrogen, carbon dioxide, and / or water (water vapor). During the foaming process, the chemical blowing agent can be activated by heating the mixture to a temperature above its decomposition temperature. The amount of chemical blowing agent in the foamable polyethylene composition is generally selected based on the desired foam density.

[0247] It is known that higher melt strength generally improves the polymer foaming process and foam quality. High pressure low density polyethylene (HPLDPE) generally contains long chain branching, which can improve the melt strength and facilitate the foaming process. However, HPLDPE resins can be limited in their end-use applications by their relatively low density. In contrast and without wishing to be bound by theory, the polyethylene compositions of the present disclosure exhibit rheological properties and melt strength that are desirable for foaming applications.

[0248] Rotomolded article

[0249] Generally, for use in a roto-molding process, the polyethylene composition is manufactured in the form of a powder or pellets. The roto-molding process can additionally include process steps for manufacturing the polyethylene composition. For roto-molding, it is preferred to use a powder and can have a particle size of less than or equal to 35 US mesh. If preferred, the polymer composition grinding can be performed at low temperature. Thereafter, the polymer powder is placed inside a hollow mold and subsequently heated within the mold while the mold is rotating. The mold is typically biaxially rotating, i.e., rotating around two perpendicular axes simultaneously. The mold is typically heated from the outside (typically with a forced air circulation oven). Generally, the roto-molding process steps include tumbling, heating and melting of the polymer powder, followed by coalescence, fusion or sintering and cooling to remove the molded article.

[0250] In certain embodiments of the present disclosure, the polyethylene compositions of the present disclosure can be processed in a commercial roto-molding machine. The time and temperature used will depend on factors including the thickness of the part being roto-molded and can be readily determined by one skilled in the art. By providing some non-limiting examples, the oven temperature during the heating step can range from 400°F to 800°F, or from about 500°F to about 700°F, or from about 575°F to about 650°F.

[0251] After the heating step, the mold is cooled. The part must cool enough to be easily removed from the mold and to retain its shape. The mold can be removed from the oven while continuing to rotate. Cool air is first blown onto the mold. The air can be at ambient temperature. After the air begins to cool the mold for a controlled period of time, water spray can be used. Water cools the mold more quickly. The water used can be at cold tap water temperature, for example, it can be from about 4°C (40°F) to about 16°C (60°F). After the water cooling step, another air cooling step can be used. This can be a short step during which the equipment is dried, removing heat during the water evaporation.

[0252] Heating and cooling cycle times will depend on the equipment used and the article being molded. Specific factors include part thickness in the mold material. As a non-limiting example, conditions for a 1 / 8 inch thick part in a steel mold can be to heat the mold in an oven with air at about 316°C (600°F) for about 15 minutes; then cool the part in ambient temperature forced air for about 8 minutes, followed by a spray of tap water at about 10°C (50°F) for about 5 minutes; optionally, the part can be re-cooled in ambient temperature forced air for 2 minutes.

[0253] During the heating and cooling steps, the mold containing the molded article is preferably continuously rotated. Typically this is done along two perpendicular axes. The rate of rotation of the mold about each axis is limited by the machine capability and the shape of the molded article. A typical, non-limiting range of operation useful in the present disclosure is to have a rotation ratio of the major axis to the minor axis of about 1 :8 to 10: 1 or about 1 :2 to 8: 1.

[0254] Non-limiting examples of articles that can be made using the rotational molding process include custom tanks, water tanks, carts, shipping and containment boxes, coolers, and sports and recreational equipment (e.g., boats, kayaks), toys, and playground equipment.

[0255] Desired physical properties of the rotational molded articles depend on the target application. Non-limiting examples of desired properties include: flexural modulus (1% and 2% secant modulus); environmental stress crack resistance (ESCR); Shore hardness; heat deflection temperature (HDT); VICAT softening point; Izod impact strength; ARM impact resistance; and color (whiteness and / or yellowness index).

[0256] In one embodiment of the present disclosure, a polyethylene composition having a melt index (I2) of 0.8 to 4.0 g / 10 min is used to make a rotational molded article having an internal volume of about 500 to 22,000 liters.

[0257] In one embodiment of the present disclosure, a method for making a rotational molded article includes the steps of: (i) loading a polyethylene composition into a mold; (ii) heating the mold in an oven to a temperature in excess of 280°C; (iii) rotating the mold about at least 2 axes; (iv) cooling the mold while the mold is rotating; and (v) opening the mold to release the rotational molded article.

[0258] Additives and adjuvants - rotomolded article

[0259] The described polyethylene compositions and rotomolded articles of manufacture can optionally include additives and adjuvants depending on their intended use. Additives can be added to the polyethylene composition during the extrusion or compounding step, although other suitable known methods will be apparent to those skilled in the art. Additives can be added as is or as part of a separate polymer component that is added during the extrusion or compounding step. Non-limiting examples of additives and adjuvants include antiblocking agents, antioxidants, heat stabilizers, slip agents, processing aids, antistatic additives, colorants, dyes, filler materials, light stabilizers, heat stabilizers, light absorbers, lubricants, pigments, plasticizers, nucleating agents, and combinations thereof. Non-limiting examples of suitable primary antioxidants include 1010 [CAS Reg. No. 6683-19-8] and IRGANOX 1076 [CAS Reg. No. 2082-79-3]; both available from BASF Corporation, Florham Park, NJ, U.S.A. Non-limiting examples of suitable secondary antioxidants include 168 [CAS Reg. No. 31570-04-4], available from BASF Corporation, Florham Park, NJ, U.S.A.; 705 [CAS Reg. No. 939402-02-5], available from Addivant, Danbury, CT, U.S.A.; and IGP-11 [CAS Reg. No. 1227937-46-3], available from Dover Chemical Corporation, Dover OH, U.S.A. Additives that can optionally be added are typically added in amounts of up to 20 percent by weight (wt. %).

[0260] One or more nucleating agents can be introduced into the polyethylene composition by kneading the polymer mixture, typically in the form of a powder or pellets, with a nucleating agent that can be used alone or in the form of a concentrate containing other additives such as stabilizers, pigments, antistatic agents, UV stabilizers, and fillers. It should be a material that is wetted or absorbed by the polymer, insoluble in the polymer, and has a melting point higher than that of the polymer, and it should be uniformly dispersed in the polymer melt in as finely divided a form as possible (1 to 10 μm). Compounds known to have nucleating ability for polyolefins include salts of aliphatic mono- or diacids or arylalkyl acids, such as sodium succinate or aluminum phenylacetate; and alkali metal or aluminum salts of aromatic or alicyclic carboxylic acids, such as sodium β-naphthoate. Another compound known to have nucleating ability is sodium benzoate. Nucleating effectiveness can be microscopically monitored by observing the degree of reduction in spherulite size resulting from crystalline aggregation.

[0261] In embodiments of the present disclosure, the described polyethylene compositions and manufactured rotomolded articles can include additives selected from the group consisting of antioxidants, phosphites and phosphonites, nitrones, anti-acids, UV light stabilizers, UV absorbers, metal deactivators, dyes, fillers and reinforcing agents, nanoscale organic or inorganic materials, antistatic agents, mold release agents such as zinc stearate, and nucleating agents (including nucleants, pigments, or any other chemical that can provide nucleation to the polyethylene composition).

[0262] In embodiments of the present disclosure, additives that can be added can be added in an amount of up to 20 percent by weight (wt. %).

[0263] Additives can be added to the described polyethylene compositions during the extrusion or compounding step, although other suitable known methods will be apparent to those skilled in the art. Additives can be added as is or as part of a separate polymer component that is added during the extrusion or compounding step.

[0264] A more detailed list of additives that can be added to the polyethylene compositions of the present disclosure and used in rotomolded articles is as follows:

[0265] Phosphites (e.g. mono-phosphite aryl Esters )

[0266] The term monoaryl phosphite as used herein refers to phosphite stabilizers that contain (1) only one phosphorus atom per molecule; and (2) at least one aryloxy (which can also be referred to as phenoxy) group bonded to the phosphorus.

[0267] In one embodiment of the present disclosure, the monoaryl phosphite contains three aryloxy groups— for example, triphenyl phosphite is the simplest member of this preferred group of monoaryl phosphites.

[0268] In another embodiment of the present disclosure, the monoaryl phosphite contains Ci to C 10 Alkyl substituents. These substituents can be straight-chained (as in the case of the nonyl substituent) or branched (as in the case of the isopropyl or t-butyl substituents).

[0269] Non-limiting examples of monoaryl phosphites useful in embodiments of the present disclosure include those selected from the group consisting of: triphenyl phosphite; diphenyl alkyl phosphites; phenyl dialkyl phosphites; tris(nonylphenyl) phosphite [WESTON 399, available from GE Specialty Chemicals]; tris(2,4-di-tert-butylphenyl) phosphite [IRGAFOS 168, available from Ciba Specialty Chemicals Corp.]; and bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite [IRGAFOS 38, available from Ciba Specialty Chemicals Corp.]; and 2,2',2"-nitrilo[tris(3,3',5,5'-tetra-tert-butyl-1,1 '-biphenyl-2,2'-diyl) phosphite] [IRGAFOS 12, available from Ciba Specialty Chemicals Corp.].

[0270] In embodiments of the present disclosure, the amount of monoaryl phosphite added to the polyethylene composition is from 200 to 2,000 ppm (based on the weight of the polymer), or from 300 to 1,500 ppm, or from 400 to 1,000 ppm.

[0271] Phosphites, phosphonites (e.g. di-phosphite, di-phosphonite)

[0272] The term diphosphite as used herein refers to a phosphite stabilizer containing at least two phosphorus atoms per phosphite molecule (and, similarly, the term diphosphonite refers to a phosphonite stabilizer containing at least two phosphorus atoms per phosphonite molecule).

[0273] Non-limiting examples of diphosphites and diphosphonites useful in embodiments of the present disclosure include those selected from the group consisting of: distearyl pentaerythritol diphosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite 626, available from GE Specialty Chemicals]; bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite; bisisodecyloxy pentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl) pentaerythritol diphosphite, bis(2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene-diphosphonite [IRGAFOS P-EPQ, available from Ciba] and bis(2,4-dicumylphenyl) pentaerythritol diphosphite [DOVERPHOS S9228-T or DOVERPHOS S9228-CT] and (CAS No 119345-01-06), which is an example of a commercially available diphosphonite.

[0274] In embodiments of the disclosure, the diphosphite and / or diphosphonite added to the polyethylene composition is added in an amount of 200 ppm to 2,000 ppm (based on the weight of the polymer), or 300 to 1,500 ppm, or 400 to 1,000 ppm.

[0275] In one embodiment of the disclosure, the use of a diphosphite is preferred over the use of a diphosphonite.

[0276] In one embodiment of the disclosure, the most preferred diphosphites are those available under the trademarks DOVERPHOS S9228-CT and ULTRANOX 626.

[0277] Hindered phenolic antioxidants

[0278] The hindered phenolic antioxidant can be any molecule conventionally used as a primary antioxidant for stabilizing polyolefins. Suitable examples include 2,6-di-tert-butyl-4- methylphenol; 2-tert-butyl-4,6-dimethylphenol; 2,6-di-tert-butyl-4-ethylphenol; 2,6-di-tert- butyl-4-n-butylphenol; 2,6-di-tert-butyl-4-isobutylphenol; 2,6-di-cyclopentyl-4-methylphenol; 2-(a- methylcyclohexyl)-4,6-dimethylphenol; 2,6-di-octadecyl-4-methylphenol; 2,4,6-tricyclohexylphenol; and 2,6-di-tert-butyl-4-methoxy-methylphenol.

[0279] Two (non-limiting) examples of suitable hindered phenolic antioxidants useful in embodiments of the disclosure are sold by BASF Corporation under the trademarks IRGANOX 1010 (CAS Registry No. 6683-19-8) and IRGANOX 1076 (CAS Registry No. 2082-79-3).

[0280] In one embodiment of the disclosure, the amount of hindered phenolic antioxidant added to the polyethylene composition is added in an amount of 100 to 2,000 ppm, or 400 to 1,000 ppm (based on the weight of the polymer).

[0281] Long term stabilizers

[0282] In embodiments of the disclosure, plastic parts intended for long-term use can contain at least one hindered amine light stabilizer (HALS). HALS are well known to those skilled in the art.

[0283] When used, in one embodiment of the disclosure, the HALS can be a commercially available material and can be used in conventional manner and in conventional amounts.

[0284] Commercially available HALS useful in embodiments of the disclosure include those sold by Ciba Specialty Chemicals Corporation under the trademarks 119; CHIMASSORB 944; CHIMAS SORB 2020; 622 and TINUVIN 770, and those sold by Cytec Industries under the trademarks UV 3346, CYASORB UV 3529, CYASORB UV 4801 and CYASORB UV 4802. In some embodiments of the disclosure, TINUVIN 622 is preferred. In other embodiments of the disclosure, mixtures of more than one HALS are also contemplated for use.

[0285] In embodiments of the disclosure, suitable HALS include those selected from the group consisting of bis(2,2,6,6-tetramethylpiperidyl)-sebacate; bis-5(l,2,2,6,6-pentamethylpiperidyl)-sebacate; n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonic acid bis(l,2,2,6,6-pentamethylpiperidyl) ester; condensation product of l-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidine and succinic acid; condensation product of N,N'-(2,2,6,6-tetramethylpiperidyl)-hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-l,3,5-s-triazine; tris-(2,2,6,6-tetramethylpiperidyl)-nitrilotriacetate, l,2,3,4-butanetetra-carbonic acid tetrakis-(2,2,6,6-tetramethyl-4-piperidyl) ester; and l,l'-(l,2-ethanediyl)-bis-(3,3,5,5-tetramethylpiperazinone).

[0286] Hydroxylamines

[0287] It is known to use hydroxylamines and derivatives thereof, including oxylamines, as additives for polyethylene compositions used to make rotomolded parts, as disclosed in U.S. Patent No. 6,444,733 and the hydroxylamines and derivatives thereof disclosed therein are also applicable.

[0288] In an embodiment of the present disclosure, the hydroxylamine useful in the polyethylene composition can be selected from N,N-dialkylhydroxylamine, a commercial example of which is N,N-di(alkyl)hydroxylamine sold as IRGASTAB 042 (by BASF) and reportedly prepared by direct oxidation of N,N-di(hydrogenated) tallow amine.

[0289] In an embodiment of the present disclosure, the polyethylene composition contains an additive package comprising: a hindered mono-phosphite; a di-phosphite; a hindered amine light stabilizer, and at least one additional additive selected from a hindered phenol and a hydroxylamine.

[0290] As a cap or lid for a molded article

[0291] In an embodiment of the present disclosure, the polyethylene composition is used to form any cap having any suitable design and size for sealing any suitable bottle, container, and the like.

[0292] In an embodiment of the present disclosure, the polyethylene composition is used to form a cap for a bottle, a container, a bag, and the like. For example, a bottle cap formed by either continuous compression molding or injection molding is contemplated. Such caps include, for example, hinged caps, hinged screw caps, hinged snap-top caps, and hinged caps for bottles, containers, bags, and the like.

[0293] In an embodiment of the present disclosure, the cap (or cap) is a screw cap for a bottle, a container, a bag, and the like.

[0294] In an embodiment of the present disclosure, the cap (or cap) is a snap cap for a bottle, a container, a bag, and the like.

[0295] In an embodiment of the present disclosure, the cap (or cap) contains a hinge made of the same material as the rest of the cap (or cap).

[0296] In an embodiment of the present disclosure, the cap (or cap) is a hinged cap.

[0297] In an embodiment of the present disclosure, the cap (or cap) is a hinged cap for a bottle, a container, a bag, and the like.

[0298] In an embodiment of the present disclosure, the cap (or cap) is a flip-top hinged cap, such as used on plastic ketchup bottles or similar containers containing food products.

[0299] When the cap is a hinged cap, it includes a hinge assembly and is generally constructed of at least two bodies connected by a thinner section acting as a hinge to allow the at least two bodies to be bent from an initial molded position. The thinner section can be continuous or web-like, wide or narrow.

[0300] Useful closures (for bottles, containers, etc.) are hinged closures and can be comprised of two bodies interconnected by at least one thinner, bendable portion (for example, the two bodies can be connected by a single bridge portion or more than one bridge portion or by a webbed portion, etc.). The first body can contain a dispensing aperture and can snap onto a container or be screwed onto a container to cover a container opening (for example, a bottle opening), while the second body can act as a snap-on lid that can cooperate with the first body.

[0301] Caps and closures (of which hinged caps and closures and screw caps are a subset) can be manufactured according to any known method, including, for example, injection molding and compression molding techniques known to those skilled in the art. Thus, in one embodiment of the disclosure, a cap (or closure) comprising a polyethylene composition (described herein) is prepared using a method comprising at least one compression molding step and / or at least one injection molding step.

[0302] In one embodiment, the closures (including single-piece or multi-piece variants and hinged variants) are well suited for sealing bottles, containers, etc., for example, bottles that can contain potable water and other foodstuffs, including, but not limited to, liquids under suitable pressure (i.e., carbonated beverages or suitably pressurized potable liquids).

[0303] The closures and caps can also be used to seal bottles containing potable water or non-carbonated beverages (for example, fruit juice). Other applications include caps and closures for bottles, containers, and pouches containing foodstuffs, for example, ketchup bottles, etc.

[0304] The closures and caps can be single-piece closures or two-piece closures comprising a closure and a liner.

[0305] The closures and caps can also have a multi-layer design, wherein the closure or cap comprises at least two layers, at least one of which is made from a polyethylene composition described herein.

[0306] In one embodiment of the disclosure, the closures are manufactured by continuous compression molding.

[0307] In one embodiment of the disclosure, the closures are manufactured by injection molding.

[0308] Further non-limiting details of the disclosure are provided in the following examples. The examples are presented for the purpose of illustrating selected embodiments of the disclosure and it is understood that the presented examples do not limit the presented claims.

[0309] Examples Applicatio Degree of observation

[0310] Prior to testing, each test specimen is conditioned at 23 ± 2°C and 50 ± 10% relative humidity for at least 24 hours, and then tested at 23 ± 2°C and 50 ± 10% relative humidity. In this document, the term "ASTM conditions" refers to a laboratory maintained at 23 ± 2°C and 50 ± 10% relative humidity; the test specimen to be tested is conditioned in this laboratory for at least 24 hours prior to testing. ASTM refers to the American Society for Testing and Materials.

[0311] Melt index

[0312] The polyethylene composition density is determined using ASTM D792-13 (November 1, 2013).

[0313] Gel permeation chromatography (GPC)

[0314] The polyethylene composition melt index is determined using ASTM D1238 (August 1, 2013). The melt indices I2, I6, I10, and I21 are measured at 190°C using 2.16 kg, 6.48 kg, 10 kg, and 21.6 kg weights, respectively. 10 and I 21 In this document, the term "stress index" or its acronym "S.Ex." is determined by the following relationship:

[0315] S.Ex. = log(I6 / I2) / log(6480 / 2160)

[0316] where I6and I2are the melt flow rates measured at 190°C using 6.48 kg and 2.16 kg loads, respectively. In this disclosure, the melt indices are expressed using units of g / 10 minutes or g / 10 min or dg / minute or dg / min; these units are equivalent.

[0317] Triple detection size exclusion chromatography (3D-SEC)

[0318] The polyethylene composition molecular weights Mw, Mn, and Mz, and polydispersity (Mw / Mn) are determined using ASTM D6474-12 (December 15, 2012). n , Mn w , and M z , and polydispersity (M w / M nPolymer sample solutions (1 to 2 mg / mL) were prepared by heating the polymer in 1,2,4-trichlorobenzene (TCB) and rotating it on a wheel at 150 °C for 4 hours in an oven. The antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT) was added to the mixture to stabilize the polymer against oxidative degradation. The BHT concentration was 250 ppm. The sample solutions were chromatographically separated at 140 °C using TCB as the mobile phase at a flow rate of 1.0 mL / min on a PL 220 high-temperature chromatography apparatus equipped with four Shodex columns (HT803, HT804, HT805, and HT806) with differential refractive index (DRI) as the concentration detector. BHT was added to the mobile phase at a concentration of 250 ppm to protect the GPC column from oxidative degradation. The sample injection volume was 200 μL. GPC software processes raw GPC data. The GPC column is calibrated using narrow-distribution polystyrene standards. The polystyrene molecular weight is converted to polyethylene molecular weight using the Mark-Houwink equation, as described in ASTM D6474-12 (December 15, 2012).

[0319] GPC-FTIR

[0320] A polyethylene composition sample (polymer) solution (1 to 3 mg / mL) was prepared by heating the polymer in 1,2,4-trichlorobenzene (TCB) and rotating it on a wheel at 150 °C for 4 hours in a furnace. An antioxidant (2,6-di-tert-butyl-4-methylphenol (BHT)) was added to the mixture to stabilize the polymer against oxidative degradation. The BHT concentration was 250 ppm. The sample solution was chromatographically separated at 140 °C on a PL 220 high-temperature chromatography apparatus equipped with a differential refractive index (DRI) detector, dual-angle light scattering detectors (15 and 90 degrees), and a differential viscometer. The SEC columns used were four Shodex columns (HT803, HT804, HT805, and HT806) or four PL Mixed ALS or BLS columns. TCB was used as the mobile phase at a flow rate of 1.0 mL / min, and BHT was added to the mobile phase at a concentration of 250 ppm to protect the SEC column from oxidative degradation. The sample injection volume was 200 μL. The raw SEC data were processed using CIRRUS GPC software to produce absolute molar mass and intrinsic viscosity ([η]). The term "absolute" molar mass was used to distinguish between the absolute molar mass determined by 3D-SEC and the molar mass determined by conventional SEC. The viscosity-average molar mass (Mn) determined by 3D-SEC was used in the calculations. v To determine the long-chain branching factor (LCBF).

[0321] Unsaturation content

[0322] A polyethylene composition (polymer) solution (2 to 4 mg / mL) was prepared by heating the polymer in 1,2,4-trichlorobenzene (TCB) and spinning on a wheel at 150 °C in an oven for 4 hours. Antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT) was added to the mixture to stabilize the polymer from oxidative degradation. The BHT concentration was 250 ppm. The sample solution was chromatographically separated on a Waters GPC 150C chromatograph equipped with four Shodex columns (HT803, HT804, HT805, and HT806) using TCB as the mobile phase at a flow rate of 1.0 milliliter / minute at 140 °C with an FTIR spectrometer and heated FTIR flow cell coupled to the chromatograph via heated transfer lines as the detection system. BHT was added to the mobile phase at a concentration of 250 ppm to protect the SEC columns from oxidative degradation. The sample injection volume was 300 μL. The raw FTIR spectra were processed with OPUS FTIR software and the polymer concentration and methyl content were calculated in real time with Chemometric software associated with OPUS (PLS technique). The polymer concentration and methyl content were subsequently retrieved and baseline corrected with CIRRUS GPC software. The SEC columns were calibrated with narrow distribution polystyrene standards. The polystyrene molecular weights were converted to polyethylene molecular weights using the Mark-Houwink equation as described in ASTM Standard Test Method D6474. The comonomer content was calculated based on the polymer concentration and methyl content predicted by the PLS technique as described in Paul J. DesLauriers, Polymer 43, pp. 159-170 (2002), which is incorporated herein by reference.

[0323] The GPC-FTIR method measures the total methyl content, which includes the methyl groups located at the end of each macromolecular chain, i.e., the methyl end groups. Therefore, the raw GPC-FTIR data must be corrected by subtracting the contribution from the methyl end groups. More specifically, the raw GPC-FTIR data overestimates the amount of short chain branching (SCB) and this overestimation increases as the molecular weight (M) decreases. In the present disclosure, a 2-methyl correction is used to correct the raw GPC-FTIR data. At a given molecular weight (M), the number of methyl end groups (N E ) is calculated using the following equation: N E = 28000 / M, and N E (dependent on M) is subtracted from the raw GPC-FTIR data to produce the SCB / 1000C (2-methyl correction) GPC-FTIR data.

[0324] Comonomer content: Fourier transform infrared (FTIR) spectroscopy

[0325] The amount of unsaturation, i.e., double bonds, in the polyethylene composition was determined according to ASTM D3124-98 (Vinylidene Unsaturations, published March 2011) and ASTM D6248-98 (Vinyl and Trans Unsaturations, published July 2012). The polymer sample: a) was first subjected to carbon disulfide extraction to remove additives that can interfere with the analysis; b) was pressed into a plate of uniform thickness (0.5 millimeter) from the sample (in pellet, film, or granular form); and c) the plate was analyzed by FTIR.

[0326] Composition distribution branching index (CDBI) by CTREF

[0327] The amount of comonomer in the polyethylene composition was determined by FTIR and reported as short chain branching (SCB) content (number of methyl branches per 1000 carbon atoms) with the dimension of CH3# / 1000C. This test was accomplished according to ASTM D6645-01 (2001) using pressed polymer plates and a Thermo-Nicolet 750Magna-IR spectrophotometer. The polymer plates were prepared using a press molding apparatus (Wabash-Genesis Series press) according to ASTM D4703-16 (April 2016).

[0328] Hexane extractables

[0329] The "Composition Distribution Branching Index" or "CDBI" of the disclosed examples and comparative examples was determined using a Crystallization-TREF apparatus ("CTREF" apparatus) commercially available from Polymer Char (Valencia, Spain). The acronym "TREF" refers to Temperature Rising Elution Fractionation. A sample (80 to 100 milligrams) of the polyethylene composition was placed in the reactor of the Polymer Char Crystallization-TREF apparatus, which was filled with 35 milliliters of 1,2,4-trichlorobenzene (TCB), heated to 150 °C and held at that temperature for 2 hours to dissolve the sample. An aliquot (1.5 milliliters) of the TCB solution was subsequently loaded into a Polymer Char TREF column, which was filled with stainless steel beads, and the column was equilibrated at 110 °C for 45 minutes. The polyethylene composition was crystallized from the TCB solution in the TREF column by slowly cooling the column from 110 °C to 30 °C using a cooling rate of 0.09 °C / minute. The TREF column was then equilibrated at 30 °C for 30 minutes. The crystallized polyethylene composition was then eluted from the TREF column by passing pure TCB solvent through the column at a flow rate of 0.75 milliliters / minute while slowly increasing the temperature of the column from 30 °C to 120 °C using a heating rate of 0.25 °C / minute. The TREF distribution curve was generated using Polymer Char software while the polyethylene composition was eluted from the TREF column, that is, the TREF distribution curve is a plot of the amount (or intensity) of polymer material eluted from the column as a function of TREF elution temperature. The CDBI was calculated from the TREF distribution curve for each analyzed polyethylene composition 50 The "CDBI 50 " is defined as the percentage of polymer whose composition is within 50% of the median comonomer composition (25% on each side of the median comonomer composition); this definition is consistent with the definition described in WO 93 / 03093 to Exxon Chemical Patents Inc; it is calculated from the TREF composition distribution curve and the normalized cumulative integral of the TREF composition distribution curve. Those skilled in the art will appreciate that a calibration curve is needed to convert TREF elution temperature to comonomer content, that is, the amount of comonomer in the polyethylene composition fraction eluted at a particular temperature. The generation of such calibration curves is described in the prior art, for example, Wild et al., J. Polym. Sci., Part B, Polym. Phys., Vol. 20(3), pp. 441-455.

[0330] Neutron activation analysis (NAA)

[0331] Hexane extractables were determined according to Code of Federal Registration 21 CFR § 177.1520 Para (c) 3.1 and 3.2; wherein the amount of hexane extractable material in the sample was determined gravimetrically.

[0332] Dynamic mechanical analysis (DMA)

[0333] Neutron Activation Analysis (hereinafter NAA) was used to determine catalyst residues in the polyethylene composition and was performed as follows. A polymer sample was loaded into a irradiation vial (consisting of ultra-pure polyethylene, 7 ml internal volume) and the sample weight was recorded. Using a pneumatic transfer system, the sample was placed in a SLOWPOKE TM Atomic Energy of Canada Limited, Ottawa, Ontario, Canada) and irradiated for 30 to 600 seconds for short half-life elements (e.g., Ti, V, Al, Mg, and Cl) or 3 to 5 hours for long half-life elements (e.g., Zr, Hf, Cr, Fe, and Ni). The average thermal neutron flux in the reactor was 5 x 10 11 / cm 2 / s. After irradiation, the sample was removed from the reactor and aged to allow for radioactive decay; 300 seconds for short half-life elements or several days for long half-life elements. After aging, the gamma-ray spectrum of the sample was recorded using a germanium semiconductor gamma-ray detector (Ortec Model GEM55185, Advanced Measurement Technology Inc., Oak Ridge, Tenn., U.S.A.) and a multi-channel analyzer (Ortec Model DSPEC Pro). The amount of each element in the sample was calculated from the gamma-ray spectrum and recorded in parts per million relative to the total weight of the polymer sample. The N.A.A. system was calibrated with Specpure standards (1,000 ppm solutions (greater than 99% pure) of the desired elements). One milliliter of solution (target element) was pipetted onto a 15 mm x 800 mm rectangular filter paper and air dried. The filter paper was then placed in a 1.4 milliliter polyethylene irradiation vial and analyzed by the N.A.A. system. The sensitivity (counts / μg) of the N.A.A. procedure was determined using the standards.

[0334] Melt strength

[0335] Oscillatory shear measurements at small strain amplitudes were performed at 190 °C under N2atmosphere, at a strain amplitude of 10% and a frequency range of 0.02-126 rad / s with 5 points per decade to obtain the linear viscoelastic function. Frequency sweep experiments were performed with a TA Instruments DHR3 stress controlled rheometer using a cone-and-plate geometry with a cone angle of 5°, a truncation of 137 μιη and a diameter of 25 mm. In this experiment a sinusoidal strain wave was applied and the stress response was analyzed as a linear viscoelastic function. The zero shear rate viscosity (η0) based on the DMA frequency sweep results was predicted by the Ellis model (see R.B. Bird et al. "Dynamics of Polymer Liquids. Volume 1 : Fluid Mechanics" Wiley-Interscience Publications (1987) page 228) or the Carreau-Yasuda model (see K. Yasuda (1979) PhD Thesis, IT Cambridge). Dynamic rheological data were analyzed using the rheometer software (i.e. Rheometrics RHIOS V4.4 or Orchestrator Software) to determine the melt elastic modulus G' at a reference melt viscous modulus (G") value of 500 Pa (G" = 500). If necessary, this value was obtained by interpolation between available data points using the Rheometrics software. The term "storage modulus", G'(ω), also called "elastic modulus", which is a function of the applied oscillatory frequency ω, is defined as the stress in phase with the strain divided by the strain in a sinusoidal deformation; while the term "viscous modulus", G"(ω), also called "loss modulus", which is also a function of the applied oscillatory frequency ω, is defined as the stress 90° out of phase with the strain divided by the strain. Both moduli and other linear viscoelastic dynamic rheological parameters are well known to those skilled in the art, for example, as discussed by G. Marin in "Oscillatory Rheometry", Chapter 10 of the book Rheological Measurement, A.A. Collyer and D.W. Clegg editors, Elsevier, 1988.

[0336] The shear thinning index SHI was calculated as the ratio of the complex viscosity estimated at a shear stress of 1 kPa to the complex viscosity estimated at a shear stress of 100 kPa (1，100) The shear thinning index SHI (1，100) It provides information on the shear thinning behavior of the polymer melt. A high value indicates a strong dependence of the viscosity on the rate of deformation (shear or frequency) variation.

[0337] The evaluation of relative elasticity is based on measurements performed at low frequencies, which are most relevant to the conditions associated with densification in powder sintering and rotational molding. The relative elasticity is evaluated based on the ratio of G' to G" at a frequency of 0.05 rad / s from DMA frequency sweep measurements performed at 190 °C. Data reported in the literature suggest that resin compositions with high relative elasticity tend to exhibit processing difficulties in slow powder densification. Wang and Kontopoulou (2004) reported sufficient rotational molding capability of a blend composition characterized by a relative elasticity as high as 0.125. In that study, the effect of plastomer content on the rotational molding capability of polypropylene was investigated (W. Q. Wang and M. Kontopoulou (2004) Polymer Engineering and Science, Vol. 44, No. 9, pp. 1662-1669). Further analysis of the results published by Wang and Kontopoulou suggests that compositions with higher plastomer content exhibit an increased relative elasticity (G' / G" > 0.13) and accordingly increased difficulty in achieving full densification during rotational molding evaluation.

[0338] In the present disclosure, the η0determined using DMA is used to determine the LCBF (long chain branching factor) (see U.S. Patent No. 10,442,921).

[0339] Long chain branching factor (LCBF)

[0340] Melt strength was measured on a Rosand RH-7 capillary rheometer (barrel diameter = 15 mm) with a flat die of 2 mm diameter, L / D ratio 10:1 at 190 °C. Pressure sensor: 10,000 psi (68.95 MPa). Piston speed: 5.33 mm / min. Haul-off angle: 52°. Haul-off incremental speed: 50-80 m / min 2 or 65 ± 15 m / min 2 The polymer melt was extruded through the capillary die at a constant rate, followed by pulling the polymer strand at increasing haul-off speed until it broke. The maximum steady state value of force in the plateau region of the force vs time curve was defined as the melt strength of the polymer. The melt strength draw ratio was defined as the ratio of the speed at the pulley relative to the speed at the die exit.

[0341] Impact properties

[0342] The LCBF (dimensionless) of the polyethylene composition was determined using the method described in U.S. Patent No. 10,442,921, which is incorporated herein by reference.

[0343] As described fully in the following paragraphs, the long chain branching factor ("LCBF") calculation requires a polydispersity corrected zero shear viscosity (ZSV c ) and a short chain branching ("SCB") corrected intrinsic viscosity (IV c ).

[0344] The zero shear viscosity ZSV c in units of poise is corrected as shown in Equation (1):

[0345]

[0346] where η0— the zero shear viscosity in poise — is measured by DMA as described above; Pd is the dimensionless polydispersity (M w / M n ) measured using conventional GPC as described above, and 1.8389 and 2.4110 are dimensionless constants.

[0347] The intrinsic viscosity IV c in units of dL / g is corrected as shown in Equation (2):

[0348]

[0349] where the intrinsic viscosity [η] (dL / g) is measured using 3D-SEC as described above; SCB has units (CH3# / 1000C) and is determined using FTIR as described above; M v — the viscosity average molar mass (g / mol) — is determined using 3D-SEC as described above, and A is a dimensionless constant that depends on the a-olefin in the ethylene / a-olefin copolymer sample, i.e., A is 2.1626, 1.9772, or 1.1398 for 1-octene, 1-hexene, and 1-butene a-olefins, respectively. In the case of ethylene homopolymers, no correction to the Mark-Houwink constant is required, i.e., SCB is zero.

[0350] "Linear" ethylene copolymers (or linear ethylene homopolymers) that contain no LCB or contain LCB at a level that is not detectable fall on the reference line defined by Equation (3).

[0351] Log(IV c ) = 0.2100 x Log(ZSV c ) - 0.7879 Equation (3)

[0352] The calculation of LCBF is based on the horizontal (S h ) and vertical (S v ) displacements from the linear reference line as defined by the following equations:

[0353] S h = Log(ZSV c )- 4.7619 x Log(IV c )- 3.7519 Equation (4)

[0354] S v = 0.2100 x Log(ZSV c )- Log(IV c )- 0.7879 Equation (5)

[0355] In Equations (4) and (5), the quantities of ZSV c and IV c are in units of Poise and dL / g, respectively. The horizontal displacement (S h ) is the displacement in ZSV c at constant intrinsic viscosity (IV c ), and if the Log function is removed, its physical meaning is apparent, i.e., the ratio of two zero shear viscosities - the ZSV c of the subject sample relative to the ZSV c of a linear ethylene copolymer (or linear ethylene homopolymer) having the same IV c . The horizontal displacement (S h ) is dimensionless. The vertical displacement (S v ) is the displacement in IV c at constant zero shear viscosity (ZSV c ), and if the Log function is removed, its physical meaning is apparent, i.e., the ratio of two intrinsic viscosities - the IV c of a linear ethylene copolymer (or linear ethylene homopolymer) having the same ZSV c relative to the IV c of the subject sample. The vertical displacement (S v ) is dimensionless.

[0356] The dimensionless long chain branching factor (LCBF) is defined by Equation (6):

[0357]

[0358] In one embodiment of the disclosure, the ethylene polymer (e.g., polyethylene composition) having LCB is characterized by having a LCBF > 0.0010 (dimensionless); in contrast, the ethylene polymer having no LCB (or no detectable LCB) is characterized by a LCBF < 0.0010 (dimensionless).

[0359] Tensile properties

[0360] Izod impact properties were determined according to ASTM D256. Notches were made to the Izod impact specimens to promote stress concentration points to induce brittle rather than ductile fracture. Tensile impact properties were determined according to ASTM D1822.

[0361] Flexural properties

[0362] The following tensile properties were determined using ASTM D 638: Elongation at Yield (%), Strength at Yield (MPa), Elongation at Break (%), Strength at Break (MPa), and 1% and 2% Secant Modulus (MPa).

[0363] Environmental stress crack resistance ESCR

[0364] Flexural properties, i.e., 2% Flexural Secant Modulus, were determined using ASTM D790-10 (published April 2010).

[0365] Preparation of polyethylene composition

[0366] Plates molded from the polyethylene compositions were tested according to the following ASTM methods: Environmental Stress Crack Resistance (ESCR) by the Bent Strip method, ASTM D1693; using a 100% solution of IGEPAL CO-630 (nonylphenoxy poly(ethyleneoxy)ethanol, branched; having the following formula: 4-(branched C9H 19 )-phenyl-[OCH2CH2] n -OH, where the subscript n is 9-10) and using a 10% solution of IGEPAL CO-630 for ESCR testing under the "B" conditions of ASTM D1693 (at a temperature of 50°C). Those skilled in the art will recognize that the testing using the 10% solution ("B 10 ") is more severe than the testing using the 100% solution ("B 100 ") in that the B 10 values are generally lower than the B 100 values.

[0367] Plates molded from the polyethylene compositions were tested according to the following ASTM methods: Environmental Stress Crack Resistance (ESCR) by the Bent Strip method, ASTM D1693; using a 100% solution of IGEPAL CO-630 (nonylphenoxy poly(ethyleneoxy)ethanol, branched; having the following formula: 4-(branched C9H 19 )-phenyl-[OCH2CH2] n- OH, where the subscript n is 9-10) and using a 10% solution of IGEPAL CO-630 for ESCR testing under ASTM D1693 "A" conditions (at a temperature of 50 °C). Those skilled in the art will recognize that testing using a 10% solution ("A 10 ") is more severe than testing using a 100% solution ("A 100 "), i.e., B 10 values are generally lower than A 100 values.

[0368] Table 1

[0369] The polyethylene composition is prepared using i) a mixed single-site catalyst system in a "tandem" dual reactor solution polymerization process or ii) a mixed single-site catalyst / multi-site catalyst system in a "tandem" dual reactor solution polymerization. As a result, the polyethylene composition comprises a first ethylene copolymer prepared with a first single-site catalyst and a second ethylene copolymer prepared with a second and different single-site catalyst or with a multi-site catalyst. The "tandem" dual reactor solution phase polymerization process, including the process using a mixed single-site catalyst, has been described in U.S. Patent Application No. 10,442,921; the "tandem" dual reactor solution phase polymerization process, including the process using a mixed single-site catalyst / multi-site catalyst, has been described in U.S. Patent Application Publication No. 2018 / 0305531. Basically, in the "tandem" dual reactor system, the outlet stream from the first polymerization reactor (R1) flows directly into the second polymerization reactor (R2). R1 pressure is from about 14 MPa to about 18 MPa; while R2 operates at a lower pressure to facilitate the continuous flow from Rl to R2. Both R1 and R2 are continuous stirred reactors (CSTRs) and are agitated to obtain conditions for the reactor contents to be well mixed. The process is operated continuously by feeding fresh process solvent, ethylene, 1-octene, and hydrogen into the reactors and removing the product (however, note that 1-octene is only fed into the first reactor). Although no comonomer is directly fed into the downstream second reactor R2, due to the substantial presence of unreacted 1-octene flowing from the first reactor to the second reactor, it copolymerizes with ethylene in the second reactor, thus an ethylene copolymer is still formed in the second reactor. Methylpentane is used as the process solvent (a commercial blend of methylpentane isomers). The volume of the first CSTR reactor (R1) is 3.2 gallons (12 liters) and the volume of the second CSTR reactor (R2) is 5.8 gallons (22 liters). The monomer (ethylene) and comonomer (1-octene) are purified prior to addition to the reactors using a conventional feed preparation system (e.g., contact with various absorption media to remove impurities such as water, oxygen, and polar contaminants). The reactor feeds are pumped to the reactors at the ratios shown in Table 1. The average residence time of the reactors is calculated by the reactor volume divided by the average flow rate, and is mainly affected by the amount of solvent flowing through each reactor and the total amount of solvent flowing through the solution process.

[0370] In the first reactor Rl, the first ethylene copolymer was produced using the following unit point catalyst components: diphenylmethlyene(cyclopentadienyl)(2,7-di-tert-butylfluorenyl) hafnium dimethyl [(2,7-tBu2Flu)Ph2C(Cp)HfMe2]; methylaluminoxane (MMAO-07); triphenylmethyl tetrakis(pentafluorophenyl)borate (trityl borate) and 2,6-di-tert-butyl-4-ethylphenol (BHEB). The methylaluminoxane (MMAO-07) was pre-mixed online with 2,6-di-tert-butyl-4-ethylphenol before being combined with the diphenylmethlyene(cyclopentadienyl)(2,7-di-tert-butylfluorenyl) hafnium dimethyl and triphenylmethyl tetrakis(pentafluorophenyl)borate just prior to entering the polymerization reactor (Rl). The efficiency of the unit point catalyst formulation was optimized by adjusting the molar ratio of the catalyst components and the Rl catalyst inlet temperature (further details are provided in Table 1).

[0371] In the second reactor R2, either a unit point catalyst (Examples 1 and 2) or a Ziegler-Natta catalyst (Examples 3 and 4) was used.

[0372] For Examples 1 and 2, the second ethylene copolymer was produced in the second reactor R2 using the following unit point catalyst components: cyclopentadienyl tris(tert-butyl) phosphinimide titanium dichloride (Cp[(t-Bu)3PN]TiCl2); methylaluminoxane (MAO-07); triphenylmethyl tetrakis(pentafluorophenyl)borate and 2,6-di-tert-butyl-4-ethylphenol. The methylaluminoxane (MMAO-07) and 2,6-di-tert-butyl-4-ethylphenol were pre-mixed online before being combined with the cyclopentadienyl tris(tert-butyl) phosphinimide titanium dichloride and triphenylmethyl tetrakis(pentafluorophenyl)borate just prior to entering the polymerization reactor (R2). The efficiency of the unit point catalyst formulation was optimized by adjusting the molar ratio of the catalyst components and the R2 catalyst inlet temperature (further details are provided in Table 1).

[0373] The solvents used for the unit point catalyst components were as follows: methylpentane for the methylaluminoxane and BHEB components; xylene for the active catalyst molecules (i.e. metallocene and phosphinimide catalysts) and triphenylmethyl borate components.

[0374] For Examples 3 and 4, the following Ziegler-Natta (ZN) catalyst components were used to produce a second ethylene copolymer in the second reactor, R2: butyl ethyl magnesium; t-butyl chloride; titanium tetrachloride; diethyl ethanolate aluminum; and triethyl aluminum. Methyl pentane was used as a catalyst component solvent and the following procedure was used to prepare an in-line Ziegler-Natta catalyst formulation which was then injected into the second reactor (R2). In Step One, a solution of triethyl aluminum and butyl ethyl magnesium (Mg:Al = 20, moles:moles) was combined with a solution of t-butyl chloride and allowed to react for approximately 30 seconds to produce a MgCl2support. In Step Two, a solution of titanium tetrachloride was added to the mixture formed in Step One and allowed to react for approximately 14 seconds before being injected into the second reactor (R2). The in-line Ziegler-Natta catalyst was activated in the reactor by injecting a solution of diethyl ethanolate aluminum into R2. The amount of titanium tetrachloride added to the reactor is shown in Table 1. The efficiency of the in-line Ziegler-Natta catalyst formulation was optimized by adjusting the molar ratio of catalyst components (further details are provided in Table 1).

[0375] The polymerization in the continuous solution polymerization process was terminated by adding a catalyst deactivator to the second reactor outlet stream. The catalyst deactivator used was octanoic acid (caprylic acid) which was purchased from P&G Chemicals, Cincinnati, OH, U.S.A. The catalyst deactivator was added such that the number of moles of fatty acid added was 50% of the total number of moles of hafnium, titanium and aluminum added to the polymerization process; for clarity, the number of moles of octanoic acid added = 0.5 x (number of moles of hafnium + number of moles of titanium + number of moles of aluminum).

[0376] A two-stage devolatilization process was employed to recover the polyethylene composition from the process solvent, i.e., two vapor / liquid separators were used and the second bottoms stream (from the second V / L separator) was passed through a gear pump / prilling machine combination. DHT-4V (hydrotalcite) supplied by Kyowa Chemical Industry Co. Ltd., Tokyo, Japan was used as a passivator or acid scavenger in the continuous solution process. A slurry of DHT-4V in process solvent was added prior to the first V / L separator.

[0377] Prior to prilling, the polyethylene composition was stabilized by adding approximately 500 ppm of Irganox 1076 (primary antioxidant) and approximately 500 ppm of Irgafos 168 (secondary antioxidant) based on the weight of the polyethylene composition. The antioxidants were dissolved in the process solvent and added between the first and second V / L separators.

[0378] Table 1 shows the reactor conditions used to prepare the polyethylene compositions of the present application. Table 1 includes process parameters such as ethylene and 1-octene split between reactors (R1 and R2), reactor temperature, ethylene conversion, etc.

[0379] Polymerization conditions

[0380] Table 2

[0381]

[0382]

[0383]

[0384] Properties of the polyethylene compositions prepared according to the present disclosure (Examples 1-4) are provided in Table 2. Table 2 also includes data for comparative polyethylene resins (Examples 5, 6, and 7).

[0385] The comparative compositions (Comparative Examples 5 and 6) were prepared in a dual reactor solution polymerization process and were prepared substantially as described in International Application No. PCT / IB 2020 / 060056 and U.S. Provisional Patent Application No. 62 / 929,304. During the preparation of Comparative Examples 5 and 6, a mixed catalyst system was employed: a single site catalyst system employing phosphinimine catalyst Cp[(t-Bu)3PN]TiCl2, which is known to not produce long chain branching, was used in the first reactor and a Ziegler-Natta catalyst, which is also known to not produce long chain branching, was used in the second reactor.

[0386] The comparative composition (Comparative Example 7) was prepared in a dual reactor solution polymerization process and was prepared substantially as described in U.S. Provisional Patent Application No. 63 / 037,754. During the preparation of Comparative Example 7, a single site catalyst system employing phosphinimine catalyst Cp[(t-Bu)3PN]TiCl2, which is known to not produce long chain branching, was used in both the first reactor and the second reactor.

[0387] Table 3 includes further data describing the polyethylene compositions prepared according to the present application, including further testing of the plaques prepared from the compositions. Table 3 also includes data for comparative polyethylene resins.

[0388] Polymer properties

[0389] Table 2 - continued

[0390]

[0391]

[0392] Polymer properties

[0393] Table 3

[0394]

[0395]

[0396] Plate properties

[0397] Table 3 - continued

[0398]

[0399]

[0400] Plate properties

[0401] Polyethylene composition deconvolution

[0402]

[0403]

[0404] Table 4

[0405] Mathematical deconvolution was performed to determine the relative amounts of the first and second ethylene copolymers present in the polyethylene composition, as well as the molecular weights (M w , M n , M z ) and comonomer content (SCB frequency per 1000 polymer backbone carbon atoms) of the first and second ethylene copolymers produced in the first and second reactors (R1 and R2), respectively.

[0406] For the deconvolution calculations, it was assumed that the unit point catalyzed ethylene copolymer components followed a Flory molecular weight distribution function, and that they had a uniform comonomer distribution across the molecular weight range.

[0407] Estimates are first obtained from predictions using a basic kinetic model with kinetic constants specific to each catalyst formulation and feed and reactor conditions. The simulation is based on the configuration of the solution plant as described above and which was used to produce the polyethylene compositions disclosed herein. The kinetic model predicts estimates for the short chain branching distribution within the first and second ethylene copolymer components. Estimates for short branch content are also validated against experimental results from GPC-FTIR for comonomer distribution. The fit between simulated molecular weight distribution curves and actual data from GPC chromatography is improved by modeling the molecular weight distribution as a sum of components with molecular weight distributions described using a multi-site idealized Flory distribution. For deconvolution, it is assumed that the unit site catalyzed polymer components follow a Flory molecular weight distribution function with uniform comonomer distribution across the molecular weight range; components produced using Ziegler-Natta catalysts are modeled using a tetra(tetra-modal) idealized Flory distribution. During deconvolution, the following relationships are used to calculate the overall M n , M w , and M z : M n = 1 / ∑(w i / (M n ) i ), M w =∑(w i ×(M w ) i ), M z =∑(w i ×(M z ) i 2 / ∑(w i ×(M zi , where i represents the i component and wi represents the relative weight fraction of the i component in the composition.

[0408] The following equations are used to calculate the density and melt index I2 for each ethylene copolymer component:

[0409] Equation (7)

[0410]

[0411] Equation (8)

[0412] p2 = (p - w1p1) / w2

[0413] Equation (9)

[0414]

[0415] where M n , M w , Mz and SCB / 1000C are the deconvoluted values of the individual ethylene polymer components obtained from the deconvolution of the results described above, and p is the density of the overall polyethylene composition and is determined experimentally. Equations (1) and (2) are used to estimate pi and p2, the densities of the first and second ethylene copolymers, respectively. Equations (3) are used to estimate the melt indices, I2, of the first and second ethylene copolymers, respectively. See, for example, Alfred Rudin, The Elements of Polymer Science and Engineering, 2ndEdition, Academic Press, 1999 and U.S. Patent No. 8,022,143. The deconvolution results are provided in Table 4.

[0416] Polymer deconvolution

[0417] Table 4 - continued

[0418]

[0419] Polymer deconvolution

[0420] Figure 1

[0421]

[0422] Note 1: The data provided in Table 4 for Example 6 (comparative) was determined using the polymerization process model outlined in International Application No. PCT / IB2020 / 060056 and U.S. Provisional Patent Application No. 62 / 929,304.

[0423] Figure 2 It is shown that the polyethylene compositions of the present disclosure (Inventive Examples 1-4) have bimodal GPC curves.

[0424] Figure 2 It is shown that the polyethylene compositions of the present disclosure (Inventive Examples 1-4) have bimodal GPC curves and that the amount of comonomer increases with increasing molecular weight, or that the comonomer content initially increases and then the amount of comonomer decreases with increasing molecular weight (as indicated by the short chain branching content, SCB / 1000 main chain carbon atoms). Thus, the comonomer distribution of Inventive Example 3 can be said to be reverse, while the comonomer distribution of Inventive Examples 1, 2, and 4 can be said to be partially reverse. Figure 3 It is shown that the comparative resins (Comparative Examples 5 and 6) have bimodal GPC curves and have reverse comonomer distributions.

[0425] Figure 4Temperature elution fractionation (TREF) curves of the polyethylene compositions prepared according to this disclosure and various comparative resins are presented. Examples 1 and 2 exhibit narrower curves compared to the other examples, indicating greater compositional uniformity. On the other hand, Examples 3 and 4 show more significant separation between elution peaks, indicating a significant difference between high-density and low-density components, consistent with results obtained from GPC-FTIR.

[0426] Figure 4 Viscosity profiles from DMA frequency scan experiments performed at 190°C on the polyethylene compositions of this disclosure and the comparative resin are presented. Although all embodiments have fairly similar molecular weight distributions (e.g., M0.05 of all embodiments...), w / M n Within the range of 4.4 to 5.9, the rheological behavior of Examples 1-4 of the present invention differs from that of Comparative Example 5. It is undesirable to be bound by theory; the shape of the viscosity curve, especially the decrease in viscosity with increasing deformation rate, will have a strong influence on the flow distribution and melt pressure requirements during extrusion and molding applications. Figure 4 It is clearly shown that Examples 1, 2, 3, and 4 of the present invention exhibit better shear-thinning behavior than Comparative Example 5, because their viscosity decreases more with increasing shear rate. This better shear-thinning behavior is also evident from the higher shear-thinning exponents observed in Examples 1-4 of the present invention relative to Comparative Example 5 (see Table 2): for each of Examples 1-4 of the present invention... (1，100) All were above 10, while for comparative example 5, SHI (1，100) The viscosity is approximately 5.0. Not wanting to be bound by theory, it is assumed that the differences in shear-thinning behavior are due to the presence of long-chain branches in Examples 1, 2, 3, and 4. Good shear-thinning behavior can be advantageous in applications with limited extrusion rates and in die-filling applications where resins typically require high flow properties. For resins with comparable molecular weights and molecular weight distributions, lower viscosity at higher deformation rates means the resin will be easier to process, requiring lower temperatures and extruder torques to achieve high throughput through the die. Similarly, resins with good shear-thinning behavior will require lower melt pressures and temperatures to fill the die cavity. Lower viscosity can be achieved by reducing the molecular weight, but this usually comes at the cost of mechanical properties. See Table 3 and... Figure 5 As shown in the data, the polyethylene compositions disclosed herein (Examples 1-4 of the present invention) have good mechanical properties (e.g., cantilever beam impact, ESCR) that are generally associated with relatively high molecular weight, as well as high flow properties (e.g., low viscosity at higher shear rates).

[0427] As can be seen from the data provided in Tables 2 and 3, the polyethylene compositions of the present disclosure (Invention Examples 1-4) have a good combination of flexural modulus at 1% (greater than about 1200 MPa), good melt strength (higher than 3.0 cN), and good ESCR (greater than 400 hours in 100% IGEPAL under Condition A or B for Invention Example 1, and greater than 1000 hours in 100% IGEPAL under Condition A or B for Invention Examples 2, 3, and 4). This balance of stiffness, melt strength, and environmental stress crack resistance is achieved even though the compositions of the present disclosure generally have a relatively high density (e.g., > 0.945 g / cm 3 ), and a relatively high melt flow rate (e.g., > 0.5 g / 10 min). In particular, Invention Examples 3 and 4 also have good Izod impact values (> 3.0 ft. lb / in). Moreover, the higher melt flow ratios (I 21 / I2) observed for Invention Examples 1-4 relative to Comparative Examples 5 and 6 can facilitate polymer processing and article formation by increasing polymer extrusion rates and / or by facilitating injection molding of narrow mold cavities.

[0428] Figure 6 The relationship between toughness (Izod impact) and stiffness (flexural modulus at 1%) for Invention Examples 1-4 and Comparative Examples 5 and 7 is further illustrated. This plot shows that the polyethylene compositions of the present disclosure have a good combination of stiffness and suitable impact properties. A particularly good balance of high stiffness and impact resistance is observed for Invention Examples 3 and 4. Without wishing to be bound by theory, the combination of high Izod impact performance and high stiffness (e.g., flexural modulus) can be important when designing molded articles.

[0429] Figure 5 The relationship between ESCR and stiffness (flexural modulus at 1%) for Invention Examples 1-4 and Comparative Examples 5 and 7 is further illustrated. This plot shows that the polyethylene compositions of the present disclosure have a balance of ESCR and stiffness that is similar to or better than Comparative Examples 5 and 7, which are polyethylene resins having slightly lower density.

[0430] In view of the data in Table 2, and the data presented in Industrial applicability and 6 , one skilled in the art will appreciate that the polyethylene compositions of the present disclosure provide a good balance of properties, including good melt strength, high stiffness (e.g., flexural modulus), reasonable impact properties (e.g., Izod and tensile impact), and good environmental stress crack resistance.

[0431] Non-limiting embodiments of the present disclosure include the following:

[0432] Embodiment A. A polyethylene composition comprising:

[0433] (i) 5 to 50 weight percent of a first ethylene copolymer having a weight average molecular weight M w > 200,000 g / mol;

[0434] (ii) 95 to 50 weight percent of a second ethylene copolymer;

[0435] wherein the first ethylene copolymer has a higher weight average molecular weight M w than the second ethylene copolymer;

[0436] wherein the first ethylene copolymer has a higher number of short chain branches per 1000 carbon atoms (SCB1) than the second ethylene copolymer (SCB2);

[0437] wherein the polyethylene composition has a density > 0.945 g / cm 3 ; a melt index I2 of 0.8 to 4.0 g / 10 min; a melt flow ratio I 21 / I2 of > 50; a molecular weight distribution M w / M n of < 6.5; a Z average molecular weight M z of > 250,000 g / mol; a Z average molecular weight distribution M z / M w of > 2.5; a long chain branching factor LCBF of > 0.0010; and an environmental stress crack resistance ESCR of greater than 400 hours determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0438] Embodiment B. The polyethylene composition of Embodiment A, wherein the polyethylene composition has a density of 0.948 g / cm 3 to 0.957 g / cm 3 .

[0439] Embodiment C. The polyethylene composition of Embodiment A or B, wherein the polyethylene composition has a melt index I2 of 1.0 to 2.5 g / 10 min.

[0440] Embodiment D. The polyethylene composition of Embodiment A, B, or C, wherein the polyethylene composition has a melt flow ratio I 21 / I2 of 60 to 130.

[0441] Embodiment E. The polyethylene composition of Embodiment A, B, C, or D, wherein the polyethylene composition has a molecular weight distribution M w / M of 3.0 to 6.0.n .

[0442] Embodiment F. The polyethylene composition of Embodiments A, B, C, D, or E, wherein the polyethylene composition has a Z average molecular weight distribution Mw / Mn of 3.0 to 5.0. z w .

[0443] Embodiment G. The polyethylene composition of Embodiments A, B, C, D, E, or F, wherein the polyethylene composition has a Z average molecular weight Mz of 250,000 g / mol to 550,000 g / mol. z .

[0444] Embodiment H. The polyethylene composition of Embodiments A, B, C, D, E, F, or G, wherein the polyethylene composition has a composition distribution breadth index CDBI of < 50%. 50 .

[0445] Embodiment I. The polyethylene composition of Embodiments A, B, C, D, E, F, or G, wherein the polyethylene composition has a composition distribution breadth index CDBI of > 60%. 50 .

[0446] Embodiment J. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, or I, wherein the first ethylene copolymer has > 2 short chain branches per 1000 carbon atoms (SCB1 / 1000C).

[0447] Embodiment K. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, or I, wherein the first ethylene has > 5 short chain branches per 1000 carbon atoms (SCB1 / 1000C).

[0448] Embodiment L. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, or K, wherein the first ethylene copolymer has a density of 0.910 to 0.932 g cm 3 .

[0449] Embodiment M. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, or L, wherein the second ethylene copolymer has a density of 0.950 to 0.970 g cm 3 .

[0450] Embodiment N. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, or M, wherein the first ethylene copolymer has a melt index I2 of < 0.5 g / 10 min.

[0451] ​Embodiment O. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, or N, wherein the second ethylene copolymer has a melt index, I2, of > 10.0 g / 10 min.

[0452] Embodiment P. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, or P, wherein the ratio of the number of short chain branches per 1000 carbon atoms in the first ethylene copolymer (SCB1 / 1000C) to the number of short chain branches per 1000 carbon atoms in the second ethylene copolymer (SCB2 / 1000C) is > 10.

[0453] Embodiment Q. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, or P, wherein the first ethylene copolymer is made with a single site catalyst.

[0454] Embodiment R. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, or Q, wherein the second ethylene copolymer is made with a single site catalyst or a Ziegler-Natta catalyst.

[0455] Embodiment S. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, or R, wherein the polyethylene composition has hafnium residuals present at least 0.050 ppm based on the weight of the polyethylene composition.

[0456] Embodiment T. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, or S, wherein the polyethylene composition has a long chain branching factor, LCBF, of > 0.0050.

[0457] Embodiment U. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, or T, wherein the polyethylene composition has a shear thinning index, SHI, of > 7.5 (1，100) .

[0458] Embodiment V. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, or T, wherein the polyethylene composition has a shear thinning index, SHI, of > 10.0 (1，100) .

[0459] Embodiment W. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, or V, wherein the polyethylene composition has a relative elasticity G’ / G” at 0.05 rad / s of < 0.50.

[0460] Embodiment X. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, or W, wherein the polyethylene composition has an Izod impact strength of > 1.5 foot pounds / inch.

[0461] Embodiment Y. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, or X, wherein the polyethylene composition has a melt strength of > 3.0 cN.

[0462] Embodiment Z. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, or Y, wherein the polyethylene composition has an environmental stress crack resistance ESCR of greater than 1000 hours determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0463] Embodiment AA. The polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, or Z, wherein the polyethylene composition has a flexural secant modulus at 1% of > 1000 MPa.

[0464] Embodiment BB. A polyethylene composition comprising:

[0465] (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight M w > 200,000 g / mol; and

[0466] (ii) 95 to 50 wt% of a second ethylene copolymer;

[0467] wherein the first ethylene copolymer has a higher weight average molecular weight M w than the second ethylene copolymer;

[0468] wherein the first ethylene copolymer has a higher number of short chain branches per 1000 carbon atoms (SCB1) than the second ethylene copolymer has a number of short chain branches per 1000 carbon atoms (SCB2);

[0469] The polyethylene composition wherein the polyethylene composition has a content of ≥0.945 g / cm³ 3 Density; melt index I2 of 0.8 to 4.0 g / 10 min; melt flow ratio I of ≥50 21 / I2; Molecular weight distribution M <6.5 w / M n Z-average molecular weight M ≥250,000 g / mol z Z-mean molecular weight distribution M > 2.5 z / M w Long chain branching factor (LCBF) > 0.0010; Compositional distribution width index (CDBI) < 50% 50 >3.0 ft-lb / in cantilever beam impact strength; and >1000 hours of environmental stress cracking resistance (ESCR) determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0470] Implementation Scheme CC. A polyethylene composition comprising:

[0471] (i) 5 to 50% by weight of M with a weight-average molecular weight >200,000 g / mol w The first ethylene copolymer; and

[0472] (ii) 95 to 50% by weight of a second ethylene copolymer;

[0473] The first ethylene copolymer has a higher weight-average molecular weight M than the second ethylene copolymer. w ;

[0474] The number of short-chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short-chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer.

[0475] The polyethylene composition wherein the polyethylene composition has a content of ≥0.945 g / cm³ 3 Density; melt index I2 of 0.8 to 4.0 g / 10 min; melt flow ratio I of ≥50 21 / I2; Molecular weight distribution M <6.5 w / M n Z-average molecular weight M ≥250,000 g / mol z Z-mean molecular weight distribution M > 2.5 z / M w Long chain branching factor (LCBF) > 0.0010; Compositional distribution width index (CDBI) > 60% 50; >1.5 foot pound / inch cantilever beam impact strength; and environmental stress crack resistance ESCR greater than 400 hours determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

[0476] Embodiment DD. A cap or lid made from the polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB, or CC.

[0477] Embodiment EE. A rotational molded article made from the polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB, or CC.

[0478] Embodiment FF. A foamed article made from the polyethylene composition of Embodiments A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, AA, BB, or CC.

[0479] While certain embodiments have been shown and described above, it is to be understood that the technology in its broader aspects is not limited to the specific details shown and described, and that certain changes can be made therein without departing from the spirit or scope of the claimed technology as defined by the appended claims and their equivalents.

[0480] Embodiments illustratively described herein can suitably be practiced in the absence of any element or elements, limitation or limitations that is / are not specifically disclosed herein. Thus, for example, the terms "comprising," "including," containing", and the like are to be construed in an open, non- limiting fashion unless the context specifically indicates otherwise. Furthermore, the terms "substantially" and "approximately" are used herein to represent an allowable quantity of deviation as understood by one of ordinary skill in the art, and without restniction to a specific deviational range unless otherwise state in the context.

[0481] The present disclosure is not limited to the particular embodiments described in this application. Many modifications and variations of this application can be made without departing from its spirit and scope, which will be apparent to those skilled in the art. Functionally equivalent methods and compositions within the scope of the present disclosure, in addition to those enumerated herein, will become apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is limited only by the terms of the appended claims and their full scope, equivalents thereto. It is to be understood that the present disclosure is not limited to particular methods, reagents, compounds, compositions or biological systems, which can of course vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0482] Furthermore, where a feature or aspect of the disclosure is described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0483] As will be understood by those skilled in the art, for any and all purposes, particularly with respect to providing a written description, all ranges disclosed herein are also intended to include any and all possible sub-ranges comprising at least one number between (and including) the two numbers no less than the lowest and no greater than the highest number, in the range. Any listed range can be easily reduced to a fraction of the lower value and a multiple of the higher value. As a non-limiting example, each range discussed herein can be easily reduced to a third of the lower value and a fraction of the higher value. As will also be understood by those skilled in the art, all language such as "up to," "at most," "at least," and the like, includes the number no less than the lowest and no greater than the highest value in the range. Finally, as will also be understood by those skilled in the art, a range includes each individual member.

[0484] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that is inconsistent with the definitions in this specification.

[0485] Other embodiments are set forth in the following claims.

[0486] ​

[0487] Provided are high density polyethylene compositions having high melt strength, good impact resistance (Izod), and good environmental stress crack resistance (ESCR). The polyethylene compositions can be suitable for use in the manufacture of molded articles.

Claims

1. A polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight Mw of > 200,000 g / mol w ; and (ii) 95 to 50 weight percent of a second ethylene copolymer; wherein said first ethylene copolymer has a weight average molecular weight Mw higher than the weight average molecular weight Mw of said second ethylene copolymer w ; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; wherein the polyethylene composition has a density of > 0.945 g / cm 3 ; a melt index, I2, of 0.8 to 4.0 g / 10 min; a melt flow ratio, I 21 / I2, of > 50; a molecular weight distribution, M w / M n , of < 6.5; a Z-average molecular weight, M z , of > 250,000 g / mol; a Z-average molecular weight distribution, M z / M w , of > 2.5; a long chain branching factor, LCBF, of > 0.0010; and an environmental stress crack resistance, ESCR, of greater than 400 hours as determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

2. The polyethylene composition of claim 1, wherein the polyethylene composition has a density of 0.948 g / cm 3 to 0.957 g / cm 3 .

3. The polyethylene composition of claim 1, wherein the polyethylene composition has a melt index, I2, of 1.0 to 2.5 g / 10 min.

4. The polyethylene composition of claim 1, wherein the polyethylene composition has a melt flow ratio, I 21 / I2, of from 60 to 130.

5. The polyethylene composition of claim 1, wherein the polyethylene composition has a molecular weight distribution Mw / Mn of 3.0 to 6.

0. w / M n .

6. The polyethylene composition of claim 1, wherein the polyethylene composition has a Z average molecular weight distribution Mz / Mw of 3.0 to 5.

0. z / M w .

7. The polyethylene composition of claim 1, wherein the polyethylene composition has a Z average molecular weight, Mz, of 250,000 g / mol to 550,000 g / mol.

8. The polyethylene composition of claim 1, wherein the polyethylene composition has a composition distribution breadth index, CDBI, of < 50% 50 .

9. The polyethylene composition of claim 1, wherein the polyethylene composition has a composition distribution breadth index, CDBI, of > 60% 50 .

10. The polyethylene composition of claim 1, wherein the first ethylene copolymer has > 2 short chain branches per 1000 carbon atoms (SCB1 / 1000C).

11. The polyethylene composition of claim 1, wherein the first ethylene has > 5 short chain branches per 1000 carbon atoms (SCB1 / 1000C).

12. The polyethylene composition of claim 1, wherein the first ethylene copolymer has a density of 0.910 to 0.932 g cm 3 .

13. The polyethylene composition of claim 1, wherein the second ethylene copolymer has a density of 0.950 to 0.970 g cm 3 .

14. The polyethylene composition of claim 1, wherein the first ethylene copolymer has a melt index, I2, of < 0.5 g / 10 min.

15. The polyethylene composition of claim 1, wherein the second ethylene copolymer has a melt index, I2, of > 10.0 g / 10 min.

16. The polyethylene composition of claim 1, wherein the ratio of the number of short chain branches per 1000 carbon atoms (SCB1 / 1000C) in the first ethylene copolymer to the number of short chain branches per 1000 carbon atoms (SCB2 / 1000C) in the second ethylene copolymer is > 10.

17. The polyethylene composition of claim 1, wherein the first ethylene copolymer is made with a single site catalyst.

18. The polyethylene composition of claim 1, wherein the second ethylene copolymer is made with a single site catalyst or a Ziegler-Natta catalyst.

19. The polyethylene composition of claim 1, wherein the polyethylene composition has hafnium residuals present at least 0.050 ppm based on the weight of the polyethylene composition.

20. The polyethylene composition of claim 1, wherein the polyethylene composition has a long chain branching factor, LCBF, of > 0.0050.

21. The polyethylene composition of claim 1, wherein the polyethylene composition has a shear thinning index, SHI, of > 7.5 (1，100) .

22. The polyethylene composition of claim 1, wherein the polyethylene composition has a shear thinning index, SHI, of > 10.0 (1，100) .

23. The polyethylene composition of claim 1, wherein the polyethylene composition has a relative elasticity, G’ / G”, at 0.05 rad / s of < 0.

50.

24. The polyethylene composition of claim 1, wherein the polyethylene composition has an Izod impact strength of > 1.5 foot pounds / inch.

25. The polyethylene composition of claim 1, wherein the polyethylene composition has a melt strength of > 3.0 cN.

26. The polyethylene composition of claim 1, wherein the polyethylene composition has an environmental stress crack resistance, ESCR, greater than 1000 hours determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

27. The polyethylene composition of claim 1, wherein the polyethylene composition has a flexural secant modulus at 1% of > 1000 MPa.

28. A polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight Mw of > 200,000 g / mol w and (ii) 50 to 95 wt% of a second ethylene copolymer having a weight average molecular weight Mw of < 200,000 g / mol. (ii) 95 to 50 wt% of a second ethylene copolymer; wherein said first ethylene copolymer has a weight average molecular weight Mw higher than the weight average molecular weight Mw of said second ethylene copolymer w ; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; The polyethylene composition wherein the polyethylene composition has a content of ≥0.945 g / cm³ 3 Density; melt index I2 of 0.8 to 4.0 g / 10 min; melt flow ratio I of ≥50 21 / I2; Molecular weight distribution M <6.5 w / M n Z-average molecular weight M ≥250,000 g / mol z Z-mean molecular weight distribution M > 2.5 z / M w Long chain branching factor (LCBF) > 0.0010; Compositional distribution width index (CDBI) < 50% 50 >3.0 ft-lb / in cantilever beam impact strength; and >1000 hours of environmental stress cracking resistance (ESCR) determined by ASTM D1693 in 100% IGEPALC-630 under conditions A and B.

29. A polyethylene composition comprising: (i) 5 to 50 wt% of a first ethylene copolymer having a weight average molecular weight Mw of > 200,000 g / mol w and (ii) 50 to 95 wt% of a second ethylene copolymer having a weight average molecular weight Mw of < 200,000 g / mol. (ii) 95 to 50 wt% of a second ethylene copolymer; wherein said first ethylene copolymer has a weight average molecular weight Mw higher than the weight average molecular weight Mw of said second ethylene copolymer w ; wherein the number of short chain branches per 1000 carbon atoms (SCB1) of the first ethylene copolymer is higher than the number of short chain branches per 1000 carbon atoms (SCB2) of the second ethylene copolymer; The polyethylene composition wherein the polyethylene composition has a content of ≥0.945 g / cm³ 3 Density; melt index I2 of 0.8 to 4.0 g / 10 min; melt flow ratio I of ≥50 21 / I2; Molecular weight distribution M <6.5 w / M n Z-average molecular weight M ≥250,000 g / mol z Z-mean molecular weight distribution M > 2.5 z / M w Long chain branching factor (LCBF) > 0.0010; Compositional distribution width index (CDBI) > 60% 5o >1.5 ft-lb / in cantilever beam impact strength; and >400 hours of environmental stress cracking resistance (ESCR) determined by ASTM D1693 in 100% IGEPAL CO-630 under conditions A and B.

30. A cap or lid prepared from the polyethylene composition of claim 1, 28, or 29.

31. A rotomolded article prepared from the polyethylene composition of claim 1, 28, or 29.

32. A foamed article prepared from the polyethylene composition of claim 1, 28, or 29.

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