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EP-4098670-B1 - BIMODAL POLY(ETHYLENE-CO-1-ALKENE) COPOLYMER

EP4098670B1EP 4098670 B1EP4098670 B1EP 4098670B1EP-4098670-B1

Inventors

  • ASKAR, SHADID
  • MARTIN, PETER S.
  • LIU, BO
  • SZUL, JOHN F.
  • KUHLMAN, ROGER L
  • KAPUR, MRIDULA BABLI

Dates

Publication Date
20260513
Application Date
20200428

Claims (13)

  1. A bimodal poly(ethylene- co -1-alkene) copolymer comprising a higher molecular weight poly(ethylene- co -1-alkene) copolymer component (HMW copolymer component) and a lower molecular weight poly(ethylene- co -1-alkene) copolymer component (LMW copolymer component), the copolymer being characterized by a combination of features comprising each of features (a) to (e) and feature (f2) and, optionally feature (g): (a) a density greater than 0.955 gram per cubic centimeter (g/cm 3 ) measured according to ASTM D792-13 (Method B, 2-propanol); (b) a first molecular weight distribution that is a ratio of M w /M n from 16 to 18, wherein M w is weight-average molecular weight and M n is number-average molecular weight, both measured by Gel Permeation Chromatography (GPC); (c) a second molecular weight distribution that is a ratio of M z /M w from 11 to 15, wherein M z is z-average molecular weight and M w is weight-average molecular weight, both measured by GPC; (d) a component weight fraction amount wherein the HMW copolymer component is less than 28 weight percent (wt%) of the combined weight of the HMW and LMW copolymer components; and (e) a high load melt index (HLMI or I 21 ) from 20 to 45 grams per 10 minutes (g/10 min.) measured according to ASTM D1238-13 (190° C., 21.6 kg); and (f2) an environmental stress-cracking resistance in hours as a function of melt flow ratio, wherein the function is defined by Equation 1: ESCR (10% Igepal, F50) > (10 * MFR5 * 1 hour) - 150 hours (Eq. 1), wherein > means greater than; * means multiplication; ESCR (10% Igepal, F50) is the number of hours to failure measured according to ASTM D1693-15, Method B; and MFR5 is a ratio of the (e) HLMI divided by a melt index I 5 expressed in g/10 min. measured according to ASTM D1238-13 (190° C., 5.0 kg); and, optionally (g) a resin swell t1000 of greater than 7.7 seconds, measured according to the Resin Swell t1000 Test Method.
  2. The bimodal poly(ethylene- co -1-alkene) copolymer of claim 1 further characterized by any one of refined features (a), (d), (e), (f1) or (f2), respectively, and (g): (a) the density is from 0.956 to 0.962 g/cm 3 ; (d) the HMW copolymer component weight fraction amount is from 17 to 27 wt%; (e) the HLMI is from 25 to 41; (f1) an ESCR (10% Igepal, F50) of from 150 to 500 hours or (f2) the ESCR (10% Igepal, F50) is a function of the MFR5 as defined by Equation 1a: ESCR (10% Igepal, F50) > (10 * MFR5 * 1 hour) - 100 hours (Eq. 1a); and (g) the resin swell t1000 is from 7.7 to 9.0 seconds.
  3. The bimodal poly(ethylene- co -1-alkene) copolymer of claim 1 or 2 further characterized by any one of features (h) to (q): (h) M w from 280,000 to 360,000 grams per mole (g/mol); (i) M n from 15,000 to 23,000 grams g/mol; (j) M z from 3,000,000 to 4,800,000 g/mol; (k) an MFR5 from 16 to 27;(I) feature (g) in combination with (f1); (m) a melt index I 5 from 0.5 to 2.0 g/10 minutes; (n) feature (g) in combination with feature (f2); (o) feature (g) in combination with feature (f1) and (f2), respectively; (p) a combination of any seven of features (h) to (o); and (q) a combination of each of features (h) to (o).
  4. The bimodal poly(ethylene- co -1-alkene) copolymer of any one of claims 1 to 3 further characterized by any one of features (r) to (w): (r) the LMW copolymer component has a M w from 45,000 to 55,000 g/mol; (s) the LMW copolymer component has a M n from 13,000 to 20,000 g/mol; (t) the LMW copolymer component has a M z from 85,000 to 115,000 g/mol; (u) the LMW copolymer component has a M w /M n ratio from 2.5 to 3.3; (v) any three of features (r) to (u); (w) each of features (r) to (u).
  5. The bimodal poly(ethylene- co -1-alkene) copolymer of any one of claims 1 to 4 further characterized by any one of features (x) to (ac): (x) the HMW copolymer component has a M w from 1,000,000 to 1,400,000 g/mol; (y) the HMW copolymer component has a M n from 220,000 to 320,000 g/mol; (z) the HMW copolymer component has a M z from 2,000,000 to 4,700,000 g/mol; (aa) the HMW copolymer component has a M w /M n ratio from 4.0 to 4.4; (ab) any three of features (x) to (aa); and (ac) each of features (x) to (aa).
  6. The bimodal poly(ethylene- co -1-alkene) copolymer of any one of claims 1 to 5 further characterized by feature (ad) a melt strength of greater than 7.0 centinewtons (cN).
  7. The bimodal poly(ethylene- co -1-alkene) copolymer of any one of claims 1 to 6 wherein the 1-alkene is 1-hexene and the bimodal poly(ethylene- co -1-alkene) copolymer is bimodal poly(ethylene-co-1-hexene) copolymer
  8. A method of making the bimodal poly(ethylene- co -1-alkene) copolymer of any one of claims 1 to 7, the method comprising contacting ethylene and 1-alkene with a bimodal catalyst system in a single polymerization reactor under effective polymerization conditions to give the bimodal poly(ethylene- co -1-alkene) copolymer; wherein the bimodal catalyst system consists essentially of a metallocene catalyst, a single-site non-metallocene catalyst that is a bis((alkyl-substituted phenylamido)ethyl)amine catalyst, optionally a host material, and optionally an activator; wherein the host material, when present, is selected from at least one of an inert hydrocarbon liquid and a solid support; wherein the metallocene catalyst is an activation reaction product of contacting an activator with a metal-ligand complex of formula (R 1-2 Cp)((alkyl) 1-3 Indenyl)MX 2 , wherein R is hydrogen, methyl, or ethyl; each alkyl independently is a (C 1 -C 4 )alkyl; M is titanium, zirconium, or hafnium; and each X is independently a halide, a (C 1 to C 20 )alkyl, a (C 7 to C 20 )aralkyl, a (C 1 to C 6 )alkyl-substituted (C 6 to C 12 )aryl, or a (C 1 to C 6 )alkyl-substituted benzyl; and wherein the bis((alkyl-substituted phenylamido)ethyl)amine catalyst is an activation reaction product of contacting an activator with a bis((alkyl-substituted phenylamido)ethyl)amine ZrR 1 2 , wherein each R 1 is independently selected from F, CI, Br, I, benzyl, -CH 2 Si(CH 3 ) 3 , a (C 1 -C 5 )alkyl, and a (C 2 -C 5 )alkenyl.
  9. The method of claim 8 having at least one of the following features: the single polymerization reactor is a single gas phase polymerization reactor; and the metal-ligand complex is of formula (I): wherein R, M, and X are as defined therein.
  10. A formulation comprising the bimodal poly(ethylene- co -1-alkene) copolymer of any one of claims 1 to 7 and at least one additive that is different than the copolymer.
  11. A method of making a manufactured article, the method comprising extruding-melt-blowing the bimodal poly(ethylene- co -1-alkene) copolymer of any one of claims 1 to 7, or the formulation of claim 10, under effective conditions so as to make the manufactured article.
  12. The manufactured article made by the method of claim 11.
  13. Use of the manufactured article of claim 12 in storing or transporting a material in need of storing or transporting.

Description

FIELD Bimodal poly(ethylene-co-1-alkene) copolymer and related methods and articles. INTRODUCTION Patent application publications and patents in or about the field include US7868092B2, US9169337B2, WO2008147968, and USSN 62/712,527 filed July 31, 2018. SUMMARY WO-A-2018/147968 relates to an ethylene-based polymer comprising a higher molecular weight component (HMW component) and a lower molecular weight component (LMW component), the ethylene- based polymer being characterized by a density greater than or equal to 0.949 g/cm3, measured according to ASTM D792, a ratio of Mw/Mn of from 25 to 35, an ESCR of at least 600 hr. measured according to ASTM D-1693, Condition B (Igepal 10%), and a bimodal weight average molecular weight distribution with a local minimum in a range of log (molecular weight) 4 to 6 between a peak representing the HMW component and a peak representing the LMW component, as determined by Gel Permeation Chromatography (GPC) analysis, of the ethylene-based polymer. WO-A-2017/044373 relates to ethylene-based polymers generally characterized by a density greater than 0.954 g/cm3, high load melt index ranging from 10 to 45 g/10 min, a ratio of high load melt index to melt index ranging from 175 to 600, a rheological slope parameter ranging from 0.15 to 0.30, and an ESCR in 10% igepal exceeding 800 hours. We discovered a bimodal poly(ethylene-co-1-alkene) copolymer. The copolymer comprises a higher molecular weight poly(ethylene-co-1-alkene) copolymer component (HMW copolymer component) and a lower molecular weight poly(ethylene-co-1-alkene) copolymer component (LMW copolymer component). The copolymer is characterized by a unique combination of features comprising, or indicated by, its density; molecular weight distributions; component weight fraction amount; and viscoelastic properties; and at least one of environmental stress-cracking resistance and resin swell. Additional inventive embodiments include a method of making the copolymer, a formulation comprising the copolymer and at least one additive that is different than the copolymer, a method of making a manufactured article from the copolymer or formulation; the manufactured article made thereby, and use of the manufactured article. DETAILED DESCRIPTION The bimodal poly(ethylene-co-1-alkene) copolymer is a composition of matter. The bimodal poly(ethylene-co-1-alkene) copolymer comprises the higher molecular weight poly(ethylene-co-1-alkene) copolymer component (HMW copolymer component) and the lower molecular weight poly(ethylene-co-1-alkene) copolymer component (LMW copolymer component). The copolymer is characterized by the unique combination of features comprising, or indicated by, its density; molecular weight distributions; component weight fraction amount; and viscoelastic properties; and at least one, alternatively each of environmental stress-cracking resistance and resin swell. Embodiments of the copolymer may be characterized by refined or additional features and/or by features of one or both of its HMW and LMW copolymer components. The copolymer is a so-called reactor copolymer because it is made in a single polymerization reactor using a bimodal catalyst system effective for simultaneously making the HMW and LMW copolymer components in situ. The same copolymer composition cannot be made by separately making the HMW copolymer component and separately making the LMW copolymer component, and then blending the separately made components together. The bimodal poly(ethylene-co-1-alkene) copolymer is a so-called reactor copolymer because it is made in a single polymerization reactor using a bimodal catalyst system effective for simultaneously making the HMW and LMW copolymer components in situ. The bimodal catalyst system comprises a so-called high molecular weight-polymerization catalyst effective for making mainly of the HMW copolymer component and a low molecular weight-polymerization catalyst effective for making mainly the LMW copolymer component. The high molecular weight-polymerization catalyst and the low molecular weight-polymerization catalyst operate under identical reactor conditions in a single polymerization reactor. It is believed that the intimate nature of the blend of the LMW and HMW copolymer components achieved in the bimodal poly(ethylene-co-1-alkene) copolymer by this in situ single reactor polymerization method could not be achieved by separately making the HMW copolymer component in the absence of the LMW copolymer component and separately making the LMW copolymer component in the absence of the HMW copolymer component, and then blending the separately made neat copolymer components together in a post-reactor process. The bimodal poly(ethylene-co-1-alkene) copolymer has improved processability. This enables manufacturing methods wherein the copolymer is melt-extruded and formed into manufactured articles. The manufactured articles include molded articles. Molded articles may be made by processes such as inject