Process for making ethylene-based polymers using carbon-carbon free radical initiators

Patent metadata

Field	Value
Publication number	US-10647789-B2
Application number	US-201615736196-A
Country	US
Kind code	B2
Filing date	Jun 21, 2016
Priority date	Jun 22, 2015
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

A composition comprising an ethylene-based polymer is made by a process comprising the steps of: (A) contacting under first polymerization conditions at least ethylene and at least one molecular catalyst to form a first ethylene-based polymer, and (B) contacting under second polymerization conditions the first ethylene-based polymer of (A) with at least additional ethylene and a carbon-carbon free radical initiator of Structure (I): wherein R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each, independently, hydrogen or a hydrocarbyl group and wherein, optionally, two or more R groups (R 1 , R 2 , R 3 , R 4 , R 5 and R 6 ) form a ring structure, with the proviso that at least one of R 2 and R 5 , and at least one of R 3 and R 6 is a hydrocarbyl group of at least two carbon atoms, to form the composition.

First claim

What is claimed is:

1. A process for making a composition comprising an ethylene-based polymer, the process comprising the steps of:
(A) contacting under first polymerization conditions at least ethylene and at least one molecular catalyst to form a first ethylene-based polymer, the molecular catalyst is a metal complex of a polyvalent aryloxyether corresponding to Structure B:

where M 3 is Hf or Zr;
Ar 4 independently at each occurrence is a substituted C 9-20 aryl group, wherein the substituents, independently at each occurrence, are selected from the group consisting of alkyl; cycloalkyl; and aryl groups; and halo-, trihydrocarbylsilyl- and halohydrocarbyl-substituted derivatives thereof, with the proviso that at least one substituent lacks co-planarity with the aryl group to which it is attached;
T 4 is a C 2-20 alkylene, cycloalkylene or cycloalkenylene group, or an inertly substituted derivative thereof;
R 21 independently at each occurrence is hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, alkoxy or di(hydrocarbyl)amino group of up to 50 atoms not counting hydrogen;

R 3 independently at each occurrence is hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, alkoxy or amino of up to 50 atoms not counting hydrogen, or two R 3 groups on the same arylene ring together or an R 3 and an R 21 group on the same or different arylene ring together form a divalent ligand group attached to the arylene group in two positions or join two different arylene rings together; and
R D , independently at each occurrence is halo or a hydrocarbyl or trihydrocarbylsilyl group of up to 20 atoms not counting hydrogen, or 2 RD groups together are a hydrocarbylene, hydrocarbadiyl, diene, or poly(hydrocarbyl)silylene group, and
(B) contacting under second polymerization conditions the first ethylene-based polymer of (A) with at least additional ethylene and a carbon-carbon free radical initiator of Structure I:

wherein R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each, independently, hydrogen or a hydrocarbyl group and wherein, optionally, two or more R groups (R 1 , R 2 , R 3 , R 4 , R 5 and R 6 ) form a ring structure, with the proviso that at least one of R 2 and R 5 , and at least one of R 3 and R 6 is a hydrocarbyl group of at least two carbon atoms, to form a polymer composition comprising a second ethylene-based polymer.

2. The process of claim 1 , in which the process takes place in one reaction zone.

3. The process of claim 1 , in which the process takes place in at least two reaction zones.

4. The process of claim 1 in which the carbon-carbon free radical initiator is of Structure II:

5. The process of claim 1 in which the first polymerization conditions include a pressure of at least 14,000 pounds per square inch (psi) and a temperature of at least 195° C.

6. The process of claim 1 in which hydrogen gas is not introduced into either step (A) or (B).

7. A process for making a composition comprising an ethylene-based polymer, the process comprising the steps of:
(A) contacting under first polymerization conditions at least ethylene and at least one molecular catalyst to form a first ethylene-based polymer, and
(B) contacting under second polymerization conditions the first ethylene-based polymer of (A) with at least additional ethylene and a carbon-carbon free radical initiator of Structure I:

wherein R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each, independently, hydrogen or a hydrocarbyl group and wherein, optionally, two or more R groups (R 1 , R 2 , R 3 , R 4 , R 5 and R 6 ) form a ring structure, with the proviso that at least one of R 2 and R 5 , and at least one of R 3 and R 6 is a hydrocarbyl group of at least two carbon atoms, to form a polymer composition comprising a second ethylene-based polymer,

wherein the first polymerization conditions include a pressure of at least 14,000 pounds per square inch (psi) and a temperature of at least 195° C.

8. The process of claim 7 , in which the process takes place in one reaction zone.

9. The process of claim 7 , in which the process takes place in at least two reaction zones.

10. The process of claim 7 in which the molecular catalyst is a metal complex of a polyvalent aryloxyether corresponding to Structure B:

where M 3 is Hf or Zr;
Ar 4 independently at each occurrence is a substituted C 9-20 aryl group, wherein the substituents, independently at each occurrence, are selected from the group consisting of alkyl; cycloalkyl; and aryl groups; and halo-, trihydrocarbylsilyl- and halohydrocarbyl-substituted derivatives thereof, with the proviso that at least one substituent lacks co-planarity with the aryl group to which it is attached;
T 4 is a C2-20 alkylene, cycloalkylene or cycloalkenylene group, or an inertly substituted derivative thereof;
R 21 independently at each occurrence is hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, alkoxy or di(hydrocarbyl)amino group of up to 50 atoms not counting hydrogen;
R 3 independently at each occurrence is hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, alkoxy or amino of up to 50 atoms not counting hydrogen, or two R 3 groups on the same arylene ring together or an R 3 and an R 21 group on the same or different arylene ring together form a divalent ligand group attached to the arylene group in two positions or join two different arylene rings together; and
R D , independently at each occurrence is halo or a hydrocarbyl or trihydrocarbylsilyl group of up to 20 atoms not counting hydrogen, or 2 RD groups together are a hydrocarbylene, hydrocarbadiyl, diene, or poly(hydrocarbyl)silylene group.

11. The process of claim 7 in which the carbon-carbon free radical initiator is of Structure II:

12. The process of claim 7 in which hydrogen gas is not introduced into either step (A) or (B).

Assignees

• Dow Global Technologies Llc

Inventors

• Ewart Sean
• Karjala Teresa
• Demirors Mehmet
• Keaton Richard
• Munjal Sarat
• Eddy Christopher

Classifications

• C08F110/02

  Ethene · CPC title

• C08F10/02 Primary

  Ethene · CPC title

• C07C15/18

  containing at least one group with formula[IMAGE cpc-sch-C07C-0954.gif] · CPC title

• C08F210/02

  Ethene · CPC title

• C08F2/34

  Polymerisation in gaseous state · CPC title