Means for increasing the molecular weight and decreasing the density of ethylene interpolymers employing mixed homogeneous catalyst formulations

Patent metadata

Field	Value
Publication number	US-11015044-B2
Application number	US-201916556369-A
Country	US
Kind code	B2
Filing date	Aug 30, 2019
Priority date	Apr 19, 2017
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

A continuous solution polymerization process is disclosed wherein at least two homogeneous catalyst formulations are employed. A first homogeneous catalyst formulation is employed in a first reactor to produce a first ethylene interpolymer and a second homogeneous catalyst formulation is employed in a second reactor to produce a second ethylene interpolymer. Optionally a third ethylene interpolymer is formed in a third reactor. The resulting ethylene interpolymer products possess desirable properties in a variety of end use applications, for example in film applications. A means for increasing the molecular weight of the first ethylene interpolymer is disclosed and/or a means for increasing the temperature of the first reactor, relative to the third homogeneous catalyst formulation. A means for reducing the (α-olefin/ethylene) weight ratio in the first reactor is disclosed and/or reducing the density of the first ethylene interpolymer, relative to the third homogeneous catalyst formulation.

First claim

What is claimed is:

1. A continuous solution polymerization process comprising:
i) injecting ethylene, a process solvent, a first homogeneous catalyst formulation, optionally one or more α-olefins and optionally hydrogen into a first reactor to produce a first exit stream comprising a first ethylene interpolymer in the process solvent;
ii) passing the first exit stream into a second reactor and injecting into the second reactor, ethylene, the process solvent, a second homogeneous catalyst formulation, optionally one or more .alpha.-olefins and optionally hydrogen to produce a second exit stream comprising a second ethylene interpolymer and the first ethylene interpolymer in the process solvent; and
iii) passing the second exit stream into a third reactor and optionally injecting into the third reactor, ethylene, a process solvent, one or more .alpha.-olefins, hydrogen, a third homogeneous catalyst formulation, under a heterogeneous catalyst formulation, or a combination thereof to produce a third exit stream comprising a third ethylene interpolymer, the second ethylene interpolymer and the first ethylene interpolymer in the process solvent;
wherein, the continuous solution polymerization process comprises one or more of the following: (I) at least a 70% reduced α-olefin/ethylene] weight ratio as defined by the following formula:

%
⁢

⁢

Reduced
⁢

[

α
-
olefin

ethylene

]

=

100
×

{

(

α
-
olefin

ethylene

)

A

-

(

α
-
olefin

ethylene

)

C

(

α
-
olefin

ethylene

)

C

}

≤

-
70

⁢
%

wherein (α-olefin/ethylene) A is calculated by dividing the weight of the α-olefin added to the first reactor by the weight of the ethylene added to the first reactor, wherein the first ethylene interpolymer having a target density is produced by the first homogeneous catalyst formulation, and (α-olefin/ethylene) C is calculated by dividing the weight of the α-olefin added to the first reactor by the weight of the ethylene added to the first reactor, wherein a control ethylene interpolymer having the target density is produced by replacing the first homogeneous catalyst formulation with a fourth homogeneous catalyst formulation; and
(II) at least a 5% improved weight average molecular weight as defined by the following formula:
% Improved M w =100%×( M w A −M w C )/ M w C

wherein Mw A is a weight average molecular weight of the first ethylene interpolymer and Mw C is a weight average molecular weight of a comparative ethylene interpolymer;
wherein the comparative ethylene interpolymer is produced in the first reactor by replacing the first homogeneous catalyst formulation with the third homogeneous catalyst formulation.

2. The process according to claim 1 further comprising:
a) adding a catalyst deactivator A to the second exit stream, downstream of the second reactor, forming a deactivated solution A; or adding a catalyst deactivator B to the third exit stream, downstream of the third reactor, forming a deactivated solution B; and
b) phase separating deactivated solution A or deactivated solution B to recover the ethylene interpolymer product.

3. The process according to claim 2 , further comprising:
c) adding a passivator to deactivated solution A or deactivated solution B forming a passivated solution, with the proviso that step c) omitted if the heterogeneous catalyst formulation is not added to the third reactor, and
d) phase separating said-deactivated solution A or deactivated solution B, or the passivated solution, to recover the ethylene interpolymer product.

4. The process according to claim 3 , wherein the first homogeneous catalyst formulation is a bridged metallocene catalyst formulation comprising:
(a) a component A of Formula (I):

wherein:
M is a metal selected from Ti, Hf, or Zr, G is selected from C, Si, Ge, Sn, or Pb,
X represents a halogen atom,
R 6 , at each occurrence is independently selected from a hydrogen atom, a C 1-20 hydrocarbyl radical, a C 1-20 alkoxy radical or a C 6-10 aryl oxide radical, these radicals may be linear, branched or cyclic or further substituted with a halogen atom, C 1-10 alkyl radicals, C 1-10 alkoxy radicals, C 6-10 aryl, or aryloxy radicals,

R 1 represents a hydrogen atom, a C 1-20 hydrocarbyl radical, a C 1-20 alkoxy radical, or a C 6-10 aryl oxide radical,
R 2 and R 3 are independently selected from a hydrogen atom, a C 1-20 hydrocarbyl radical, a C 1-20 alkoxy radical, or a C 6-10 aryl oxide radical, and
R 4 and R 5 are independently selected from a hydrogen atom, a C 1-20 hydrocarbyl radial, a C 1-20 alkoxy radical, or a C 6-10 aryl oxide radical;
b) a component M A , comprising an alumoxane co-catalyst;
c) a component B A , comprising a boron ionic activator; and
d) optionally, a component P A , comprising a hindered phenol.

5. The process according to claim 4 , having the following molar ratios in the first reactor: component B A to component A from about 0.3:1 to about 10:1;component M A to component A from about 1:1 to about 300:1; and optional component P A to component M A from 0.0:1 to about 1:1.

6. The process according to claim 5 , wherein component M A is methylalumoxane (MMAO-7).

7. The process according to clai

Assignees

• Nova Chem Int Sa

Inventors

• Zhang Zengrong
• Kazemi Niousha
• Salomons Stephen
• Kleczek Monika
• Keshtkar Mehdi
• Molloy Brian
• Wang Qinyan
• Zoricak Peter
• Carter Charles
• Wang Xiaochuan
• Dobbin Christopher
• Sibtain Fazle
• Taylor Kenneth
• Vanasseldonk Lawrence
• Khakdaman Hamidreza

Classifications

• C08L2314/06

  Metallocene or single site catalysts · CPC title

• C08L2314/02

  Ziegler natta catalyst · CPC title

• C08L2207/07

  Long chain branching · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title