Bridged metallocene catalyst systems with switchable hydrogen and comonomer effects

Patent metadata

Field	Value
Publication number	US-9040643-B2
Application number	US-201314109997-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Oct 7, 2010
Publication date	May 26, 2015
Grant date	May 26, 2015

Abstract

The present invention provides polymerization processes utilizing an ansa-metallocene catalyst system for the production of olefin polymers. Polymers produced from the polymerization processes have properties that vary based upon the presence or the absence of hydrogen and/or comonomer in the polymerization process.

First claim

We claim:

1. An olefin polymerization process, the process comprising:
contacting a catalyst composition with an olefin monomer and optionally an olefin comonomer under polymerization conditions to produce an olefin polymer having less than about 0.002 long chain branches per 1000 total carbon atoms, wherein the catalyst composition comprises:
(i) an activator; and
(ii) an ansa-metallocene compound having formula (I):
E(Cp A R A m )(Cp B R B n )MX q   (I),

wherein:
M is Ti, Zr, Hf, Cr, Sc, Y, La, or a lanthanide;
Cp A and Cp B independently are a cyclopentadienyl, indenyl, or fluorenyl group;
each R A and R B independently is H or a hydrocarbyl, hydrocarbylsilyl, hydrocarbylamino, or hydrocarbyloxide group having up to 18 carbon atoms;
E is a bridging chain of 3 to 8 carbon atoms or 2 to 8 silicon, germanium, or tin atoms, wherein any substituents on atoms of the bridging chain independently are H or a hydrocarbyl group having up to 18 carbon atoms;
each X independently is F; Cl; Br; I; methyl; benzyl; phenyl; H; BH 4 ; OBR 2 or SO 3 R, wherein R is an alkyl or aryl group having up to 18 carbon atoms; or a hydrocarbyloxide group, a hydrocarbylamino group, or a hydrocarbylsilyl group, any of which having up to 18 carbon atoms;
m is 0, 1, 2, 3, or 4;
n is 0, 1, 2, 3, or 4;
q is 2 when M is Ti, Zr, or Hf; and
q is 1 when M is Cr, Sc, Y, La, or a lanthanide.

2. The process of claim 1 , wherein the process is conducted in the presence of added hydrogen in a range from about 50 ppm to about 1000 ppm; and wherein:
a Mw/Mn ratio of an olefin polymer produced by the process in the presence of an olefin comonomer is at least 25% greater than a Mw/Mn ratio of an olefin polymer produced by the process under the same polymerization conditions without an olefin comonomer; or
a Mw of an olefin polymer produced by the process in the presence of an olefin comonomer is at least 50% greater than a Mw of an olefin polymer produced by the process under the same polymerization conditions without an olefin comonomer; or
both.

3. The process of claim 1 , wherein the process is conducted in the presence of added hydrogen and the olefin comonomer; and wherein:
a Mw of the olefin polymer is substantially constant over a range of from about 50 ppm to about 1000 ppm added hydrogen; or
an activity of the catalyst composition is substantially constant over a range of from about 50 ppm to about 1000 ppm added hydrogen; or
both.

4. The process of claim 1 , wherein a molar ratio of olefin comonomer to olefin monomer is in a range from about 0.001:1 to about 0.2:1.

5. The process of claim 4 , wherein:
the process is conducted in the absence of added hydrogen; and
a Mw/Mn ratio of the olefin polymer increases as the molar ratio of olefin comonomer to olefin monomer increases from about 0.001:1 to about 0.06:1.

6. The process of claim 4 , wherein an activity of the catalyst composition decreases as the molar ratio of olefin comonomer to olefin monomer increases from about 0.001:1 to about 0.06:1.

7. The process of claim 1 , wherein the olefin polymer has:
an average of from 0 to about 5 short chain branches per 1000 total carbon atoms and a density of greater than about 0.92 g/cm 3 .

8. The process of claim 1 , wherein the process is conducted in a batch reactor, slurry reactor, gas-phase reactor, solution reactor, high pressure reactor, tubular reactor, autoclave reactor, or a combination thereof.

9. The process of claim 1 , wherein the olefin monomer is ethylene, and the olefin comonomer comprises propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutylene, 1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 2-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene, 1-octene, 1-decene, styrene, or a mixture thereof.

10. The process of claim 1 , wherein the activator comprises an aluminoxane compound, an organoboron or organoborate compound, an ionizing ionic compound, or any combination thereof.

11. The process of claim 1 , wherein the activator comprises an activator-support comprising a solid oxide treated with an electron-withdrawing anion, wherein:
the solid oxide comprises silica, alumina, silica-alumina, silica-coated alumina, aluminum phosphate, aluminophosphate, heteropolytungstate, titania, zirconia, magnesia, boria, zinc oxide, a mixed oxide thereof, or any mixture thereof; and
the electron-withdrawing anion comprises sulfate, bisulfate, fluoride, chloride, bromide, iodide, fluorosulfate, fluoroborate, phosphate, fluorophosphate, trifluoroacetate, triflate, fluorozirconate, fluorotitanate, phospho-tungstate, or any combination thereof.

12. The process of claim 1 , wherein the catalyst composition further comprises an organoaluminum compound having the formula:
Al(X A ) p (X B ) 3-p ,

wherein:
X A is a hydrocarbyl;
X B is an alkoxide or an aryloxide, a halide, or a hydride; and
p is from 1 to 3, inclusive.

13. The process of claim 1 , wherein the ansa-metallocene compound having formula (I) comprises:

or a combination thereof.

14. A polymerization process, the process comprising:
contacting a catalyst composition with ethylene and optionally an α-olefin comonomer under polymerization conditions to produce an ethylene polymer, wherein the catalyst composition comprises:
(i) an activator; and
(ii) an ansa-metallocene compound having formula (I):
E(Cp A R A m )(Cp B R B n )MX q   (I),

wherein:
M is Ti, Zr, or Hf;
Cp A and Cp B independently are a cyclopentadienyl, indenyl, or fluorenyl group;
each R A and R B independently is H or a hydrocarbyl, hydrocarbylsilyl, hydrocarbylamino, or hydrocarbyloxide group having up to 18 carbon atoms;
E is —SiMe 2 —SiMe 2 —;
each X independently is F; Cl; Br; I; methyl; benzyl; phenyl; H; BH 4 ; OBR 2 or SO 3 R, wherein R is an alkyl or aryl group having up to 18 carbon atoms; or a hydrocarbyloxide group, a hydrocarbylamino group, or a hydrocarbylsilyl group, any of which having up to 18 carbon atoms;
m is 0, 1, 2, 3, or 4;
n is 0, 1, 2, 3, or 4; and
q is 2.

15. The process of claim 14 , wherein:
the catalyst composition further comprises an organoaluminum compound;
the activator comprises an activator-support comprising a solid oxide treated with an electron-withdrawing anion; and
the α-olefin comonomer comprises 1-butene, 1-hexene, 1-octene, or a combination thereof.

16. The process of claim 14 , wherein the process is conducted in the presence of added hydrogen in a range from about 50 ppm to about 1000 ppm; and wherein:
a Mw/Mn ratio of an ethylene polymer produced by the process in the presence of an α-olefin comonomer is at least 25% greater than a Mw/Mn ratio of an ethylene polymer produced by the process under the same polymerization conditions without an α-olefin comonomer; or
a Mw of an ethylene polymer produced by the process in the presence of an α-olefin comonomer is at least 50% greater than a Mw of an ethylene polymer produced by the process under the same polymerization conditions without an α-olefin comonomer; or
both.

17. The process of claim 14 , wherein the process is conducted in the presence of added hydrogen and the α-olefin comonomer, and wherein:
a Mw of the ethylene polymer is substantially constant over a range of from about 50 ppm to about 1000 ppm added hydrogen; or
an activity of the catalyst composition is substantially constant over a range of from about 100 ppm to about 500 ppm

Assignees

• Chevron Phillips Chemical Co

Inventors

• Buck Richard M
• Yang Qing
• Masino Albert P
• Wittner Christopher E

Classifications

• C08F4/65927 Primary

  two cyclopentadienyl rings being mutually bridged · CPC title

• C08F4/65908

  in combination with an ionising compound other than alumoxane, e.g. (C6F5)4B-X+ · CPC title

• C08F210/16 Primary

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08F110/02

  Ethene · CPC title

• C08F4/63916

  supported on a carrier, e.g. silica, MgCl2, polymer · CPC title