Polyethylene Composition

• US 20180134828A1
• Filed: 04/19/2016
• Published: 05/17/2018
• Est. Priority Date: 04/20/2015
• Status: Active Grant

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: DOUFAS, Antonios K., SANDERS, David F., HOLTCAMP, Matthew W., YE, Xuan, NORMAN, Alexander I., HULE, Rohan A., RANGWALLA, Hasnain
• Granted Patent: US 10,618,989 B2
• Time in Patent Office: Days
• CPC Class Codes: B01J 31/2295 Cyclic compounds, e.g. cyclopentadienyls
• CPC Class Codes: C08F 110/02 Ethene
• CPC Class Codes: C08F 210/14 Monomers containing five or more carbon atoms
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2410/07 Catalyst support treated by an anion, e.g. Cl-, F-, SO42-
• CPC Class Codes: C08F 2420/02 Cp or analog bridged to a non-Cp X anionic donor
• CPC Class Codes: C08F 2500/04 Broad molecular weight distribution, i.e. Mw/Mn > 6
• CPC Class Codes: C08F 2500/11 Melt tension or melt strength
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/13 Environmental stress cracking resistance
• CPC Class Codes: C08F 2500/17 Viscosity
• CPC Class Codes: C08F 2500/18 Bulk density
• CPC Class Codes: C08F 2800/10 as molar percentages
• CPC Class Codes: C08F 4/65904 in combination with another component of C08F4/64
• CPC Class Codes: C08F 4/65912 in combination with an organoaluminium compound
• CPC Class Codes: C08F 4/65916 supported on a carrier, e.g. silica, MgCl2, polymer
• CPC Class Codes: C08F 4/6592 containing at least one cyclopentadienyl ring, condensed or not, e.g. an indenyl or a fluorenyl ring
• CPC Class Codes: C08F 4/65927 two cyclopentadienyl rings being mutually bridged

Abstract

This invention relates to ethylene polymers obtained using a catalyst system comprising fluorided silica, alkylalumoxane activator and at least two metallocene catalyst compounds (a bridged monocyclopentadienyl group 4 transition metal compound and a biscyclopentadientyl group 4 transition metal compound), where the fluorided support has not been calcined at a temperature of 400° C. or more, and is preferably produced using a wet mixing method, such as an aqueous method. The ethylene polymers have: 1) at least 50 mol % ethylene; 2) a reversed comonomer index, mol %, (RCI,m) of 85 or more; 3) a Comonomer Distribution Ratio-2 (CDR-2,m) of the percent comonomer at the z average molecular weight divided by the percent comonomer at the weight average molecular weight plus the number average molecular weight divided by 2 ([% comonomer at Mz]/[% comonomer at ((Mw+Mn)/2)] as determined by GPC of 2.3 or more; and 4) a density of 0.91 g/cc or more.

Claims

1. A process to produce ethylene copolymer comprising:

i) contacting, in the gas phase or slurry phase, ethylene and one or more C₃ to C₂₀ comonomers, with a catalyst system comprising the reaction product of fluorided silica support, alkylalumoxane activator and at least two metallocene catalyst compounds, where the first metallocene is a bridged monocyclopentadienyl group 4 transition metal compound and the second metallocene is a biscyclopentadientyl group 4 transition metal compound where the fluorided silica support has not been calcined at a temperature of 400°

C. or more; and

ii) obtaining an ethylene polymer having;

1) at least 50 mol % ethylene;

2) a reversed comonomer index, mol %, (RCI,m) of 85 or more;

3) a Comonomer Distribution Ratio-2 (CDR-2,m) of the mole percent comonomer at the z average molecular weight divided by the mole percent comonomer at the weight average molecular weight plus the number average molecular weight divided by 2 ([% comonomer at Mz]/[% comonomer at ((Mw+Mn)/2)] as determined by GPC of 2.3 or more; and

4) a density of 0.91 g/cc or more.

2. The process of claim 1, wherein the metallocenes are represented by the formula:

T_yCp_mMG_nX_q

wherein each Cp is, independently, a cyclopentadienyl group which may be substituted or unsubstituted, M is a group 4 transition metal, G is a heteroatom group represented by the formula JR*_z where J is N, P, O or S, and R* is a linear branched or cyclic hydrocarbyl group having from one to twenty carbon atoms and z is 1 or 2, T is a bridging group, and y is 0 or 1, X is a leaving group, and m=1 or 2, n=0, 1, 2 or 3, q=0, 1, 2 or 3, and the sum of m+n+q is equal to the oxidation state of the transition metal;

wherein m=1, n=1 and y=1 in the first metallocene catalyst compound; and

n=0 and m=2 in the second metallocene catalyst compound.

3. The process of claim 2, wherein y is one in the second metallocene compound and at least one Cp in the second metallocene compound is not a substituted or unsubstituted indene group.

4. The process of claim 2 or claim 3, wherein each Cp is a cyclopentadiene, indene or fluorene, which may be substituted or unsubstituted, each M is titanium, zirconium, or hafnium, and each X is, independently, a halide, a hydride, an alkyl group, an alkenyl group or an arylalkyl group.

5. The process of claim 1, wherein the activator comprises an alkylalumoxane and a non-coordinating anion.

6. The process of claim 1, the molar ratio of the monocyclopentadienyl transition metal compound to the biscyclopentadienyl transition metal compound is from 1:

1 to 10;

1 and the comonomer is C3 to C12 alpha olefin, preferably butene, hexene and/or octene.

7. The process of claim 1, wherein for the bridged monocyclopentadienyl transition metal compound m is one, n is one, where J is N, and R* is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, cyclooctyl, cyclododecyl, decyl, undecyl, dodecyl, adamantyl or an isomer thereof.

8. The process of claim 1, wherein the bridged monocyclopentadienyl transition metal compound comprises one or more of:

Me₂Si(Me₄Cp)(cyclododecylamido)TiMe₂;

Me₂Si(Me₄Cp)(cyclododecylamido)TiCl₂;

Me₂Si(Me₄Cp)(t-butylamido)TiMe₂;

Me₂Si(Me₄Cp)(t-butylamido)TiCl₂;

μ

-(CH₃)₂Si(Cp)(1-adamantylamido)M(R)₂;

μ

-(CH₃)₂Si(3-t-BuCp)(1-adamantylamido)M(R)₂;

μ

-(CH₃)₂Si(Me₄Cp)(1-adamantylamido)M(R)₂;

μ

-(CH₃)₂Si(Me₄Cp)(1-adamantylamido)M(R)₂;

μ

-(CH₃)₂C(Me₄Cp)(1-adamantylamido)M(R)₂;

μ

-(CH₃)₂Si(Me₄Cp)(1-tertbutylamido)M(R)₂;

μ

-(CH₃)₂Si(Flu)(1-tertbutylamido)M(R)₂;

μ

-(CH₃)₂Si(Me₄Cp)(1-cyclododecylamido)M(R)₂;

μ

-(C₆H₅)₂C(Me₄Cp)(1-cyclododecylamido)M(R)₂;

μ

-(CH₃)₂Si(η

⁵-2,6,6-trimethyl-1,5,6,7-tetrahydro-s-indacen-1-yl)(tertbutylamido)M(R)₂;

where M is selected from a group consisting of Ti, Zr, and Hf and R is selected from halogen or C1 to C5 alkyl, Cp is cyclopentadienyl, Flu is fluorenyl.

9. The process of claim 1, wherein the second metallocene compound comprises one or more of:

(THI)₂HfMe₂;

(1-Bu,3-MeCp)₂ZrCl₂, (n-BuCp)₂ZrCl₂, (Me₂Si)₂O(Ind)₂ZrCl₂;

Me₂Si(3-(3-MeBu)Cp)(2,3,4,5-Me₄Cp)ZrCl₂;

Me₂Si(THI)ZrCl₂;

Me₂Si-(3-Ph-Ind)(Me₄Cp)ZrCl₂;

Me₂Si(3-neopentylCp)(Me₄Cp)HfCl₂;

Tetramethyldisilylene bis(4-(3,5-di-t-BuPh)-indenyl)ZrCl₂;

(Cp)(1,3-diPhCp)ZrCl₂;

(Cp)₂ZrCl₂;

(Me₅Cp)₂ZrCl₂;

(Me₅Cp)₂ZrMe₂;

(Me₅Cp)₂HfCl₂;

(Me₅Cp)₂ZrMe₂;

(1-Me-3-n-BuCp)₂ZrCl₂;

(1-Me-3-n-BuCp)₂ZrMe₂;

(1-Me-3-n-BuCp)₂HfCl₂;

(1-Me-3-n-BuCp)₂ZrMe₂;

(Ind)₂ZrCl₂;

(Ind)₂ZrMe₂;

bis(tetrahydro-1-indenyl)ZrCl₂;

bis(tetrahydro-1-indenyl)ZrMe₂;

Me₂Si(THI)₂ZrCl₂;

Me₂Si(THI)₂ZrMe₂;

Me₂Si(Ind)₂ZrCl₂;

Me₂Si(Ind)₂ZrMe₂;

Me₂Si(Cp)₂ZrCl₂; and

Me₂(Cp)₂ZrMe₂, where Cp is cyclopentadienyl, Ind is indenyl, Ph is phenyl, and THI is tetrahydroindenyl.

10. The process of claim 1 any one of the preceding claim, wherein the first and second metallocene compounds comprise one or more of:

SiMe₂(Me₄Cp)(cC₁₂N)TiMe₂ and bis(1-Bu,3-Me-Cp) ZrCl₂;

SiMe₂(Me₄Cp)(cC₁₂N)TiMe₂ and (SiMe₂) bis(indenyl)ZrCl₂;

SiMe₂(Me₄Cp)(cC₁₂N)TiMe₂ and (SiMe₂)₂Obis(indenyl)ZrCl₂;

SiMe₂(Me₄Cp)(cC₁₂N)TiMe₂ and (SiMe₂)₂O bis(indenyl)ZrMe₂;

SiMe₂(Me₄Cp)(cC₁₂N)TiMe₂ and SiMe₂(3-neopentylCp)((Me₄Cp)HfCl₂;

SiMe₂(Me₄Cp)(cC₁₂N)TiMe₂ and SiMe₂(3-neopentylcyclopentadienyl)(Me₄Cp)HfMe₂;

SiMe₂(Me₄Cp)(1-adamantylamido)TiMe₂ and bis(1-Bu,3-MeCp)ZrCl₂; and

SiMe₂(Me₄Cp)(1-t-butylamido)TiMe₂ and bis(1-Bu,3-MeCp)ZrCl₂.

11. The process of claim 1, wherein the fluorided support has been calcined at a temperature of 100 to less than 400°

C.

12. The process of claim 1, wherein the ethylene polymer has Comonomer Distribution Ratio-1, CDR-1,w of the percent comonomer at the z average molecular weight divided by the percent comonomer at the weight average molecular weight (% comonomer Mz/% comonomer Mw) as determined by GPC of 2.0 or more.

13. The process of claim 1, wherein the ethylene polymer has a Comonomer Distribution Ratio-3 (CDR-3,w) of the percent comonomer at the z average molecular weight plus the weight average molecular weight divided by 2 divided by the percent comonomer at the weight average molecular weight plus the number average molecular weight divided by 2 ([% comonomer at ((Mz+Mw)/2)]/[% comonomer at ((Mw+Mn)/2)] as determined by GPC of 2.2 or more.

14. The process of claim 1, wherein the process occurs at a temperature of from about 0°

C. to about 300°

C., at a pressure in the range of from about 0.35 MPa to about 10 MPa, and at a time up to 300 minutes.

15. The process of claim 1, wherein the comonomer is selected from propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene or a mixtures thereof.

16. An ethylene polymer having:

1) a density of 0.910 g/cc or more,

     2) an ethylene content of 50 mol % or more, based upon the weight of the polymer;

     3) a reversed comonomer index, mol %, (RCI,m) of 85 or more;

     4) a Comonomer Distribution Ratio-2 (CDR-2,m) of the mole percent comonomer at the z average molecular weight divided by the mole percent comonomer at the weight average molecular weight plus the number average molecular weight divided by 2 ([% mole comonomer at Mz]/[% mole comonomer at ((Mw+Mn)/2)] as determined by GPC of 2.3 or more.

17. The polymer of claim 16 having a density of 0.935 g/cc or more.

18. The polymer of claim 16 having

a) a RCI,m of 90 or more;

and/or

b) a RCI,w of 2.2 or more; and

/or

c) Comonomer Distribution Ratio-1, CDR-1,w, of the weight percent comonomer at the z average molecular weight divided by the weight percent comonomer at the weight average molecular weight (% comonomer Mz/% comonomer Mw) as determined by GPC of 2.0 or more, and/or

d) a Comonomer Distribution Ratio-2 (CDR-2,w) of the weight percent comonomer at the z average molecular weight divided by the weight percent comonomer at the weight average molecular weight plus the number average molecular weight divided by 2 ([% comonomer at Mz]/[% comonomer at ((Mw+Mn)/2)] as determined by GPC of 2.2 or more; and

/or

e) a Comonomer Distribution Ratio-3 (CDR-3,w) of the weight percent comonomer at the z average molecular weight plus the weight average molecular weight divided by 2 divided by the weight percent comonomer at the weight average molecular weight plus the number average molecular weight divided by 2 ([% comonomer at ((Mz+Mw)/2)]/[% comonomer at ((Mw+Mn)/2)] as determined by GPC of 2.2 or more; and

/or

f) an I2 of 0.01-10 g/10 min; and

/or

g) an I5 of 0.05-50 g/10 min; and

/or

h) an 121.6 of 0.1-100 g/10 min; and

/or

i) a Melt strength via rheotens at 190°

C. (die temperature) of greater than 7.5 cN; and

/or

j) a shear thinning ratio via SAOS η

*(0.01 rad/s)/η

*(118 rad/s) greater than 20, where the viscosity ratio referring to 190°

C. and η

* is the complex viscosity; and

/or

k) a strain hardening ratio (SHR) via SER at 150°

C. of at least 2.8 at a Hencky strain rate of 0.01 s<sup>−

1</sup> and/or at least 2.5 at a Hencky strain rate of 1 s<sup>−

1</sup>; and

/or

l) an environmental stress crack resistance, ESCR, (10% Igepal, 50°

C., Condition B) of greater than 700 hours (F50) (on the average of 10 specimens).

19. The polymer of claim 17 where the polymer has an environmental stress crack resistance, ESCR, (10% Igepal, 50°

C., Condition B) of greater than 1000 hours (F50) (on the average of 10 specimens).

20. The polymer of claim 17 where the polymer has a Melt strength via rheotens at 190°

C. (die temperature) of greater than 7.5 cN.

21. The polymer of claim 16, wherein the polymer has a density of 0.938 g/cc or more, a Comonomer Distribution Ratio-1, CDR-1,w, of the weight percent comonomer at the z average molecular weight divided by the weight percent comonomer at the weight average molecular weight (% comonomer Mz/% comonomer Mw) as determined by GPC of 2.2 or more, a Comonomer Distribution Ratio-2 (CDR-2,w) of the weight percent comonomer at the z average molecular weight divided by the weight percent comonomer at the weight average molecular weight plus the number average molecular weight divided by 2 ([% comonomer at Mz]/[% comonomer at ((Mw+Mn)/2)] as determined by GPC of 2.2 or more, and a Comonomer Distribution Ratio-3 (CDR-3,w) of the weight percent comonomer at the z average molecular weight plus the weight average molecular weight divided by 2 divided by the weight percent comonomer at the weight average molecular weight plus the number average molecular weight divided by 2 ([% comonomer at ((Mz+Mw)/2)]/[% comonomer at ((Mw+Mn)/2)] as determined by GPC of 2.2 or more.

22. A blend comprising the polymer of claim 16 and a second ethylene polymer comprising a polymer of ethylene and optionally one or more C₃ to C₂₀ alphaolefins and having an M_w of 20,000 to 1,000,000 g/mol and a density of 0.87 to 0.96 g/cm³.

23. The blend of claim 22 wherein the second copolymer comprises at least 50 wt % ethylene and having up to 35 wt % of a C₃ to C₂₀ comonomer, based upon the weight of the copolymer and a composition distribution breadth index (CDBI) of 60% or more, and preferably has a density of 0.910 to less than 0.930 g/cc.

24. An article comprising the blend of claim 16 and has an ESCR of 700 hours or more.

25. The polymer of claim 17, having a crystallinity from 45% to 80% (measured by WAXS) and intercrystalline crystalline spacing Lp1 of over 250 Å

(measured by SAXS) and a ratio for primary to secondary crystal interlammer spacing of at least 40.