Gas phase polymerisation of ethylene

Patent metadata

Field	Value
Publication number	US-10745495-B2
Application number	US-201716070536-A
Country	US
Kind code	B2
Filing date	Jan 19, 2017
Priority date	Jan 21, 2016
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

The invention relates to a process for the production of polyethylene by gas phase polymerisation of ethylene in the presence of a supported chromium oxide based catalyst which is modified with an amino alcohol wherein the molar ratio of amino alcohol:chromium ranges between 0.5:1 and 1.5:1 wherein the support is silica having a surface area (SA) between 250 m2/g and 400 m2/g and a pore volume (PV) between 1.1 cm3/g and less than 2.0 cm3/g.

First claim

The invention claimed is:

1. A process for the production of polyethylene by gas phase polymerisation of ethylene in the presence of a supported chromium oxide based catalyst composition which is modified with an amino alcohol wherein the molar ratio of amino alcohol: chromium ranges between 0.5:1 and 1.5:1, wherein the support is silica having a surface area (SA) between ≥450 m 2 /g and ≤550 m 2 /g and a pore volume (PV) between ≥1.7 cm 3 /g and ≤2.0 cm 3 /g and wherein the catalyst comprises a titanium compound.

2. The process according to claim 1 characterised in that the amount of chromium in the supported catalyst is ≥0.1% by weight and ≤0.5% by weight.

3. The process according to claim 1 , characterised in that the molar ratio of amino alcohol:chromium ranges between 0.7:1 and 1.5:1.

4. The process according to claim 1 , characterised in that the molar ratio of amino alcohol:chromium ranges between 1:1 and 1.3:1.

5. The process according to claim 1 , characterised in that the amino alcohol has the formula

wherein
the R groups may be, independently of one other the same or different, a C 1 -C 10 alkyl group, and
R 1 is a C 3 -C 8 cycloalkyl group or a C 4 -C 16 alkyl substituted cycloalkyl group.

6. The process according to claim 5 characterised in that the amino alcohol is 4-(cyclohexylamino) pentan-2-ol or 4-[(2-methylcyclohexyl) amino]pentan-2-ol.

7. The process according to claim 1 , characterised in that the titanium compound a compound according to the formulas Ti(OR 1 ) n X 4-n and Ti(R 2 ) n X 4-n , wherein
R 1 and R 2 represent an (C 1 -C 20 ) alkyl group, (C 1 -C 20 ) aryl group or (C 1 -C 20 ) cycloalkyl group,
X represents a halogen atom, and
n represents a number satisfying 0≥n≤4.

8. The process according to claim 1 characterised in that
the amount of chromium in the supported catalyst is ≥0.1% by weight and ≤0.5% by weight,
the molar ratio of amino alcohol:chromium ranges between 1:1 and 1.3:1, and
the amino alcohol has the formula

wherein
the R groups may be, independently of one other the same or different, a C 1 -C 10 alkyl group, and
R 1 is a C 3 -C 8 cycloalkyl group or a C 4 -C 16 alkyl substituted cycloalkyl group.

9. The process according to claim 8 characterised in that the titanium compound is a compound according to the formulas Ti(OR 1 ) n X 4-n and Ti(R 2 ) n X 4-n , wherein
R 1 and R 2 represent an (C 1 -C 20 ) alkyl group, (C 1 -C 20 ) aryl group or (C 1 -C 20 ) cycloalkyl group,
X represents a halogen atom, and
n represents a number satisfying 0≥n≤4.

Assignees

• Sabic Global Technologies Bv

Inventors

• Hamed Orass
• Aliyev Vugar
• Al-Sayari Omar

Classifications

• C08F110/02 Primary

  Ethene · CPC title

• C08F2410/06

  Catalyst characterized by its size · CPC title

• C08F2410/04

  Dual catalyst, i.e. use of two different catalysts, where none of the catalysts is a metallocene · CPC title

• C08F4/6423

  Component of C08F4/64 containing at least two different metals · CPC title

• C08F2/34 Primary

  Polymerisation in gaseous state · CPC title