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US-12624137-B2 - Ethylene interpolymer products having a melt flow-intrinsic viscosity index (MFIVI)

US12624137B2US 12624137 B2US12624137 B2US 12624137B2US-12624137-B2

Abstract

This disclosure relates to ethylene interpolymer products comprising a Melt Flow-Intrinsic Viscosity Index value, MFIVI, of from ≥0.05 to ≤0.80; a first derivative of a melt flow distribution function, formula (I) of form ≥−1.85 to ≤−1.51; an unsaturation ratio, UR, of from >0.06 to ≤0.60; and a residual catalytic metal of from ≥0.03 to ≤5 ppm of hafnium. Ethylene interpolymer products comprise at least two ethylene interpolymers. Ethylene interpolymer products are characterized by a melt index (I 2 ) from 0.3 to 500 dg/minute, a density from 0.855 to 0.975 g/cc and from 0 to 25 mole percent of one or more a-olefins. Ethylene interpolymer products have polydispersity, M w /M n , from 1.7 to 25; and CDBI 50 values from 1% to 98%. These ethylene interpolymer products have utility in flexible and rigid applications. d ⁢ Log ⁡ ( 1 / I n ) d ⁢ Log ⁡ ( loading ) ( I )

Inventors

  • Zengrong Zhang
  • Fazle Sibtain
  • Stephen Brown
  • Monika Kleczek

Assignees

  • NOVA CHEMICALS (INTERNATIONAL) S.A.

Dates

Publication Date
20260512
Application Date
20210723

Claims (11)

  1. 1 . An ethylene interpolymer product comprising at least two ethylene interpolymers, wherein the ethylene interpolymer product comprises: a) a dimensionless Melt Flow-Intrinsic Viscosity Index, MFIVI, of from ≥0.05 to ≤0.80, as defined by Eq.1 MFIVI = ( 1.9507 × ( f bimodality × f comon ⁢ om _ ⁢ er I f ) 0.21678 IV + 3.0122 × 10 - 6 × ( Comonomer ⁢ Wt . ⁢ % ) × M v 0.725 ) - 1 Eq . 1 wherein, f bimodality , is defined by Eq.2, f bimodality =10 (−0.94831×Log(Pd)−0.94322xC f −0.71879) Eq.2 wherein a polydispersity of said ethylene interpolymer product, Pd (in Eq.2), is determined by Size Exclusion Chromatography (SEC), Pd=M w /M n , where M w and M n are a weight average and a number average molecular weight, respectively; wherein, a correction factor, C f , (in Eq.2) is determined according to the following two steps (i) and (ii), (i) a melt flow distribution function of said ethylene interpolymer product defined by Eq.3, Log(1 /I n )=β 0 +β 1 ×Log(loading)+β 2 ×(Log(loading)) 2 Eq.3 wherein β 0 , β 1 , and β 2 are regression coefficients of the melt flow distribution function, and wherein the regression coefficients are determined by fitting a polynomial to experimental data of Log(1/I n ) versus Log(loading), where I n is a measured melt index, of said ethylene interpolymer product, at loadings of 21600, 10000, 6480 and 2160 grams, measured at 190° C. according to ASTM D1238, (ii) a first derivative of said melt flow distribution function is defined by Eq.4, d ⁢ Log ⁡ ( 1 / I n ) d ⁢ Log ⁡ ( loading ) = β 1 + 2 × β 2 × Log ⁡ ( loading ) Eq . 4 and said correction factor, C f (Eq.2), is the value of said first derivative (Eq.4) at a loading of 4000 g; wherein a comonomer weight percent, Comonomer Wt % (Eq.1), is the weight percent of comonomer in said ethylene interpolymer product as measured by FTIR according to ASTM D6645, if Comonomer Wt % is >14.95%, a comonomer factor, f comonomer (Eq.1), is defined by Eq.5, if Comonomer Wt % is ≤14.95%, said comonomer factor is defined by Eq.6, f comonomer =10 (0.018790×(Comonomer Wt %)−0.28053) Eq.5 f comonomer =1 Eq.6; wherein a fitted melt index, I f (Eq.1), of said ethylene interpolymer product, is determined by the value of said melt flow distribution function (Eq.3) at a loading of 4000 g; wherein, IV and M v (Eq.1) are an intrinsic viscosity and a viscosity average molar mass, respectively, of said ethylene interpolymer product as determined by 3D-SEC; b) said first derivative, d ⁢ Log ⁡ ( 1 / I n ) d ⁢ Log ⁡ ( loading ) (Eq.4) at a loading of 4000 g, having values from ≥−1.85 to ≤−1.51; c) a dimensionless unsaturation ratio, UR, of from >0.06 to ≤0.6, wherein UR is defined by the following relationship; UR=(SC U −T U )/ T U wherein, SC U is the amount of a side chain unsaturation per 100 carbons and T U is amount of a terminal unsaturation per 100 carbons, in said ethylene interpolymer product, as determined by ASTM D3124-98 and ASTM D6248-98; and d) a residual catalytic metal of from ≥0.03 to ≤5 ppm of hafnium, wherein the residual catalytic metal is measured using neutron activation.
  2. 2 . The ethylene interpolymer product of claim 1 , wherein the ethylene interpolymer product comprises a first ethylene interpolymer, a second ethylene interpolymer, and optionally a third ethylene interpolymer.
  3. 3 . The ethylene interpolymer product of claim 1 , wherein the ethylene interpolymer product has a melt index from 0.3 to 500 dg/minute and a density from 0.855 to 0.975 g/cc, wherein the melt index is measured according to ASTM D1238 (2.16 kg load and 190° C.) and the density is measured according to ASTM D792.
  4. 4 . The ethylene interpolymer product of claim 1 , wherein the ethylene interpolymer product further comprises from 0 to 25 mole percent of one or more α-olefins.
  5. 5 . The ethylene interpolymer product of claim 4 , wherein the one or more α-olefins comprise a C 3 to C 10 α-olefin.
  6. 6 . The ethylene interpolymer product of claim 5 , wherein the one or more α-olefins are 1-hexene, or 1-octene, or a mixture 1-hexene and 1-octene.
  7. 7 . The ethylene interpolymer product of claim 1 , wherein the ethylene interpolymer product has a polydispersity, M w /M n from 1.7 to 25.
  8. 8 . The ethylene interpolymer product of claim 1 , wherein the ethylene interpolymer product has a CDBI 50 from 1% to 98%, wherein CDBI 50 is measured using CTREF.
  9. 9 . The ethylene interpolymer product of claim 1 , wherein the ethylene interpolymer product is manufactured by a solution polymerization process.
  10. 10 . The ethylene interpolymer product of claim 2 , wherein the said first and said second interpolymers, or said first and said third ethylene interpolymers, or said first, said second and said third ethylene interpolymers are synthesized using a bridged metallocene catalyst formulation.
  11. 11 . The ethylene interpolymer product of claim 10 , wherein said bridged metallocene catalyst formulation comprises a component A defined by Formula (I): wherein: M is Ti, Hf, or Zr; G is C, Si, Ge, Sn, or Pb; X, at each occurrence, is independently selected from a halogen atom, H, a C 1-20 hydrocarbyl radical, a C 1-20 alkoxy radical, or a C 6-10 aryl oxide radical, wherein these radicals may be linear, branched, or cyclic or further substituted with a halogen atom, a C 1-10 alkyl radical, a C 1-10 alkoxy radical, a C 6-10 aryl, or an aryloxy radical; R 1 is H, a C 1-20 hydrocarbyl radical, a C 1-20 alkoxy radical, a C 6-10 aryl oxide radical, or an alkylsilyl radical containing at least one silicon atom and C 3-30 carbon atoms; R 2 and R 3 are independently selected from H, a C 1-20 hydrocarbyl radical, a C 1-20 alkoxy radical, a C 6-10 aryl oxide radical, or an alkylsilyl radical containing at least one silicon atom and C 3-30 carbon atoms; and R 4 and R 5 are independently selected from H, a C 1-20 hydrocarbyl radical, a C 1-20 alkoxy radical, a C 6-10 aryl oxide radical, or an alkylsilyl radical containing at least one silicon atom and C 3-30 carbon atoms.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. National Phase Application under 35 U.S.C. § 371 of International Application No. PCT/IB2021/056672, filed on Jul. 23, 2021, which in turn claims priority to and the benefit of U.S. Provisional Patent Application No. 63/070,448, filed Aug. 26, 2020, both of which are incorporated herein by reference in their entirety. BACKGROUND ART Solution polymerization processes are typically carried out at temperatures that are above the melting point of the ethylene homopolymer or copolymer produced. In a typical solution polymerization process, catalyst components, solvent, monomers and hydrogen are fed under pressure to one or more reactors. For ethylene polymerization, or ethylene copolymerization, reactor temperatures can range from 80° C. to 300° C. while pressures generally range from 3 MPag to 45 MPag. The ethylene homopolymer or copolymer produced remains dissolved in the solvent under reactor conditions. The residence time of the solvent in the reactor is relatively short, for example, from 1 second to 20 minutes. The solution process can be operated under a wide range of process conditions that allow the production of a wide variety of ethylene polymers. Post reactor, the polymerization reaction is quenched to prevent further polymerization, by adding a catalyst deactivator. Optionally, the deactivated solution may be passivated by adding an acid scavenger. The deactivated solution, or optionally the passivated solution, is then forwarded to polymer recovery where the ethylene homopolymer or copolymer is separated from process solvent, unreacted residual ethylene and unreacted optional α-olefin(s). In solution polymerization there is a need for improved processes that produce ethylene interpolymers at higher production rates, i.e. the pounds of ethylene interpolymer produced per hour is increased. Higher production rates increase the profitability of the solution polymerization plant. The catalyst formulations and solution polymerization processes disclosed herein satisfy this need. In solution polymerization there is also a need to increase the molecular weight of the ethylene interpolymer produced at a given reactor temperature. Given a specific catalyst formulation, it is well known to those of ordinary experience that polymer molecular weight increases as reactor temperature decreases. However, decreasing reactor temperature can be problematic when the viscosity of the solution becomes too high. As a result, in solution polymerization there is a need for catalyst formulations that produce high molecular weight ethylene interpolymers at high reactor temperatures (or lower reactor viscosities). The catalyst formulations and solution polymerization processes disclosed herein satisfy this need. In the solution polymerization process there is also a need for catalyst formulations that are very efficient at incorporating one or more α-olefins into a propagating macromolecular chain. In other words, at a given [α-olefin/ethylene] weight ratio in a solution polymerization reactor, there is a need for catalyst formulations that produce lower density ethylene/α-olefin copolymers. Expressed alternatively, there is a need for catalyst formulations that produce an ethylene/α-olefin copolymer, having a specific density, at a lower [α-olefin/ethylene] weight ratio in the reactor feed. Such catalyst formulations efficiently utilize the available α-olefin and reduce the amount of α-olefin in solution process recycle streams. The catalyst formulations and solution process disclosed herein, produce unique ethylene interpolymer products that have desirable properties in a variety of end-use applications. One non-limiting end-use application includes packaging films containing the disclosed ethylene interpolymer products. Non-limiting examples of desirable film properties include improved optical properties, lower seal initiation temperature and improved hot tack performance. Films prepared from the ethylene interpolymer products, disclosed herein, have improved properties. SUMMARY OF DISCLOSURE In this disclosure ethylene interpolymer products are disclosed comprising at least two ethylene interpolymers, wherein the ethylene interpolymer product has: a dimensionless Melt Flow-Intrinsic Viscosity Index value, MFIVI, of from ≥0.05 to ≤0.80, a first derivative of a melt flow distribution function, d⁢Log⁡(1/In)d⁢Log⁡(loading) at a loading of 4000 g, of from ≥−1.85 to ≤−1.51; a residual catalytic metal of from ≥0.03 to ≤5 ppm of hafnium and a dimensionless unsaturation ratio, UR, of from >0.06 to ≤0.60. The ethylene interpolymer product may have a melt index (I2) from 0.3 to 500 dg/minute, a density from 0.855 to 0.975 g/cc and contain from 0 to 25 mole percent of one or more α-olefins. Suitable α-olefins include one or more C3 to C10 α-olefins. Embodiments of the ethylene interpolymer product may have a polydispersity, Mw/Mn, from 1.7 to 25, where Mw and Mn are