Process for Producing Polymer Compositions

• US 20170362350A1
• Filed: 12/28/2015
• Published: 12/21/2017
• Est. Priority Date: 01/14/2015
• Status: Active Grant

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Canich, Jo Ann M., Kolb, Rainer, Ravishankar, Periagaram S., Matsunaga, Phillip T., Jiang, Peijun, Shah, Rhutesh K., Dharmarajan, Narayanaswami
• Granted Patent: US 10,457,801 B2
• Time in Patent Office: Days
• CPC Class Codes: C08F 2/001 Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer C08F295/00, C08F297/00 take precedence
• CPC Class Codes: C08F 210/06 Propene
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 210/18 with non-conjugated dienes, e.g. EPT rubbers
• CPC Class Codes: C08F 236/20 unconjugated
• CPC Class Codes: C08F 2500/04 Broad molecular weight distribution, i.e. Mw/Mn > 6
• CPC Class Codes: C08F 2500/09 Long chain branches
• CPC Class Codes: C08F 2500/17 Viscosity
• CPC Class Codes: C08F 4/65904 in combination with another component of C08F4/64
• CPC Class Codes: C08F 4/65908 in combination with an ionising compound other than alumoxane, e.g. (C6F5)4B-X+
• CPC Class Codes: C08F 4/65927 two cyclopentadienyl rings being mutually bridged
• CPC Class Codes: C08F 4/76 selected from titanium, zirconium, hafnium, vanadium, niobium or tantalum
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/025 containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• CPC Class Codes: C08L 2205/06 having improved processability or containing aids for moulding methods
• CPC Class Codes: C08L 2207/07 Long chain branching
• CPC Class Codes: C08L 23/16 Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
• CPC Class Codes: C08L 2312/04 with phenolic resin
• CPC Class Codes: C08L 2314/06 Metallocene or single site catalysts

Abstract

Processes are provided which include copolymerization using one or both of a metallocene catalyst capable of producing high molecular weight polymers and a metallocene catalyst capable of producing polymers having 60% or more vinyl terminations. Polymerization processes include dual catalyst polymerization in a single polymerization zone comprising both metallocene catalysts. Other processes include serial or parallel polymerizations in multiple polymerization zones, using either or both catalysts in each polymerization zone. Such polymerization processes produce reactor blends, and are particularly suited for producing copolymer compositions (such as EP or EPDM copolymer compositions) exhibiting improved melt elasticity and rheological properties.

Claims

1. A polymerization process comprising:

copolymerizing a plurality of monomers comprising (i) a first C₂-C₂₀ α

-olefin monomer;

(ii) a second C₂-C₂₀ α

-olefin monomer different from the first, and optionally; and

(iii) one or more dienes in the presence of a vinyl-terminated polymer-forming (VTP) catalyst system and a high molecular weight polymer-forming (HMP) catalyst system, thereby forming a copolymer composition comprising one or more copolymers;

wherein;

(a) the HMP catalyst system comprises a HMP catalyst compound and a first activator;

(b) the VTP catalyst system comprises a VTP catalyst compound and a second activator; and

(c) the VTP catalyst compound has the structural formula;

2. The process of claim 1, wherein the first C₂-C₂₀ α

-olefin monomer is ethylene, and the second C₂-C₂₀ α

-olefin monomer is one of propylene and butene.

3. The process of claim 1, wherein the plurality of monomers comprises one or more dienes.

4. The process of claim 3, wherein the one or more dienes are selected from the group consisting of:

5-ethylidene-2-norbornene (ENB), 5-vinyl-2-norbornene (VNB), 1,4-hexadiene, dicyclopentadiene, and any combination thereof.

5. The process of claim 1, wherein the copolymerizing takes place in a plurality of polymerization zones comprising at least a first polymerization zone and a second polymerization zone.

6. The process of claim 5, wherein the copolymerizing comprises:

copolymerizing the plurality of monomers in the first polymerization zone in the presence of the VTP catalyst system to provide a polymerization intermediate comprising one or more vinyl-terminated polymers (VTPs) and at least a portion of the plurality of monomers; and

copolymerizing the polymerization intermediate in the presence of the HMP catalyst system in the second polymerization zone to obtain the copolymer composition.

7. The process of claim 5, wherein the copolymerizing comprises:

copolymerizing a first portion of the plurality of monomers in the presence of the VTP catalyst system in the first polymerization zone to provide a polymerization intermediate; and

copolymerizing a second portion of the plurality of monomers and the polymerization intermediate in the presence of the HMP catalyst system in the second reactor zone to obtain the copolymer composition.

8. The process of claim 6, wherein the copolymerizing comprises:

copolymerizing a first portion of the plurality of monomers in the first polymerization zone in the presence of the VTP catalyst system to provide a first polymerization intermediate;

copolymerizing a second portion of the plurality of monomers in the second polymerization zone in the presence of the HMP catalyst system to provide a second polymerization intermediate; and

blending the first and second polymerization intermediates to obtain the copolymer composition.

9. The process of claim 6, wherein the HMP catalyst system is disposed in both the first polymerization zone and the second polymerization zone, such that the first polymerization zone constitutes a dual catalyst zone containing both the VTP catalyst system and the HMP catalyst system, and the second polymerization zone contains the HMP catalyst system.

10. The process of claim 1, wherein the copolymerizing takes place at least in part in a dual polymerization zone in which both the HMP catalyst system and the VTP catalyst system are present, such that 3.5-5.0 mol HMP catalyst compound have been provided to the dual polymerization zone per 1 mol VTP catalyst compound provided to the dual polymerization zone.

11. The process of claim 1, wherein, within the VTP catalyst compound:

(1) each R³ is hydrogen;

(2) each R⁴ is independently a C₁-C₁₀ alkyl;

(3) each R² and R⁷ is independently hydrogen, or C₁-C₁₀ alkyl, (4) each R⁵ and R⁶ is independently hydrogen, C₁-C₅₀ substituted or unsubstituted hydrocarbyl, or C₁-C₅₀ substituted or unsubstituted halocarbyl;

(5) R⁴ and R⁵, R⁵ and R⁶, and/or R⁶ and R⁷ may optionally be bonded together to form a ring structure; and

(6) J is represented by the formula R^a₂J′

, where J′

is C or Si, and each R^a is, independently, C₁ to C₂₀ substituted or unsubstituted hydrocarbyl, provided that the two R^a may be bonded together to form a saturated or partially saturated cyclic or fused ring structure that incorporates J′

.

12. The process of claim 11, wherein the two R^a in the formula R^a₂J′

are bonded together to form a saturated or partially saturated cyclic or fused ring structure that incorporates J′

.

13. The process of claim 12, wherein, within the VTP catalyst compound, J is selected from the group consisting of:

cyclopentamethylenesilylene, cyclotetramethylenesilylene, and cyclotrimethylenesilylene.

14. The process of claim 11, wherein, within the VTP catalyst compound, R² is independently selected from the group consisting of hydrogen, methyl, ethyl, propyl, butyl, pentyl, heptyl, hexyl, octyl, nonyl, decyl and isomers thereof;

and further wherein R⁴ is independently selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, heptyl, hexyl, octyl, nonyl, decyl and isomers thereof.

15. The process of claim 14, wherein the VTP catalyst compound comprises cyclotetramethylenesilylene-bis(2,4,7-trimethylinden-1-yl)hafnium dimethyl.

16. The process of claim 1, wherein the HMP catalyst compound is selected from mono-cyclopentadienyl amido group 4 transition metal complexes;

mono-CP amido variants;

bridged fluorenyl-cyclopentadienyl group 4 transition metal complexes;

Cp-fluorenyl variants;

biphenyl phenol (BPP) transition metal complexes;

pyridyl amide transition metal complexes;

pyridyl diamide transition metal complexes; and

any combination thereof.

17. The process of claim 16, wherein the HMP catalyst compound comprises a mono-cyclopentadienyl amido group 4 transition metal complex having the following structural formula:

18. The process of claim 17, wherein the mono-cyclopentadienyl amido group 4 metal complex is selected from the group consisting of:

dimethyl silylene(tetramethylcyclopentadienyl) (cyclododecylamido) titanium dimethyl;

dimethylsilylene(trimethylcyclopentadienyl) (adamantylamido) titanium dimethyl;

dimethyl silylene(2-methyl-1,5,6,7-tetrahydro-s-indacen-1-yl)(tert-butylamido) titanium dimethyl;

dimethylsilylene(2,6,6-trimethyl-1, 5,6,7-tetrahydro-s-indacen-1-yl)(tert-butylamido) titanium dimethyl; and

any combination thereof.

19. The process of claim 16, wherein the HMP catalyst compound comprises one or more of the following:

(I) a biphenyl phenol (BPP) transition metal complex of the following structural formula;

20. The process of claim 16, wherein the HMP catalyst compound comprises a bridged fluorenyl-cyclopentadienyl group 4 transition metal complex having the structural formula:

21. The process of claim 20, wherein the HMP catalyst compound comprises 1,1′

-bis(4-triethylsilylphenyl)methylene-(cyclopentadienyl)(2,7-di-tertiary-butyl-fluoren-9-yl)hafnium dimethyl.

22. The process of claim 1, wherein each of the first and second activators is independently represented by the formula:

(Z)d⁺(A^d−

)

wherein A^d−

is a non-coordinating anion having the charge d−

;

d is an integer from 1 to 3, and Z is a reducible Lewis acid.

23. The process of claim 22 wherein each of the first and second activators is independently N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(perfluoronaphthyl)borate, or both.

24. The process of claim 23 wherein the first activator is N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, and the second activator is N,N-dimethylanilinium tetrakis(perfluoronaphthyl)borate.

25. The process of any one of the foregoing claims, wherein the copolymer composition has one or more of the following properties:

(i) corrected Mooney Large Relaxation Area (cMLRA) at Mooney Large Viscosity (ML)=80 Mooney Units (mu), such that cMLRA is from 240 to 2000 mu*sec, where ML is determined at (1+4@125°

C.);

(ii) MLRA/ML ratio greater than R, where R is given as R=9.57(ML)−

40.83, where ML is the Mooney Large Viscosity of the copolymer composition determined at (1+4@125°

C.);

(iii) shear thinning index (STI) measured at 125°

C. greater than 0.950;

(iv) a phase angle δ

at complex shear modulus G*=100,000 Pa of less than 54.5°

;

(v) Mw/Mn greater than or equal to 3.5;

(vi) LCB index measured at 125°

C. of less than 5; and

(vii) relaxation time τ

(determined at 125°

C. using the Cross equation) of greater than 1.4 sec.