Process for preparing higher molecular weight polyisobutylene

Patent metadata

Field	Value
Publication number	US-9963521-B2
Application number	US-201313765031-A
Country	US
Kind code	B2
Filing date	Feb 12, 2013
Priority date	Feb 17, 2012
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

Preparation of isobutene homopolymers having a weight-average molecular weight of 75 000 to 10 000 000 by polymerization of isobutene, by
(a) performing the polymerization at −80° C. to −190° C., (b) using, as an inert solvent, optionally halogenated C 1 to C 5 hydrocarbons, (c) using, as a polymerization catalyst, a Lewis acid complex, (d) performing the polymerization in the presence of at least one reaction accelerator in the form of an ethylenically saturated hydrocarbon compound comprising one oxygen atom and no abstractable proton, and (e) performing the polymerization in the presence of at least one chain length regulator comprising one tertiary olefinic carbon atom.

First claim

The invention claimed is:

1. A process for preparing an isobutene homopolymer having a weight-average molecular weight of 75,000 to 10,000,000, by polymerization of isobutene in the liquid phase in an inert solvent in the presence of a polymerization catalyst based on Lewis acids, which comprises, in a polymerization reactor, at the same time
(a) performing the polymerization at temperatures of −140° C. to −190° C.,
(b) using, as an inert solvent, one or more C 1 to C 8 hydrocarbons or one or more halogenated C 1 to C 8 hydrocarbons or a mixture thereof and
(c) using, a complex of boron trifluoride and a C 1 - to C 4 -alkanol as a polymerization catalyst,
and additionally
(d) performing the polymerization in the presence of at least one aldehyde reaction accelerator,
and
(e) performing the polymerization in the presence of diisobutene as a chain length regulator,
wherein the isobutene polymer obtained in the polymerization reactor is discharged from the polymerization reactor at temperatures of less than −80° C. and subjected to purification by a process consisting essentially of a thermal purification process using one or more extruders at temperatures of more than +80° C.;
wherein an inert gas which is different from said inert solvent is introduced into one or more segments of said one or more extruders; and
wherein polymerization is conducted to a conversion of 85 to 100% of isobutene.

2. The process according to claim 1 , wherein, as measure (a), the polymerization is performed at temperatures of less than −160° C. to −185° C.

3. The process according to claim 1 , wherein measure (a) is executed by bringing the polymerization medium to the required low temperature and keeping it there during the polymerization by means of a separate cooling circuit.

4. The process according to claim 1 , wherein, as measure (b), the inert solvent used is at least one inert solvent selected from the group consisting of ethane, ethene, propane, propene, n-butane, isobutane or a mixture thereof.

5. The process according to claim 1 , wherein, as measure (b), the inert solvent used is 1,1,1,2,3,3,3-heptafluoropropane, octafluoropropane or a mixture thereof.

6. The process according to claim 1 , wherein the polymerization conditions are selected such that the isobutene used is converted in the polymerization reactor with a conversion of at least 90% to isobutene homopolymers having a weight-average molecular weight of 75,000 to 10,000,000.

7. The process according to claim 1 , wherein said inert gas comprises nitrogen.

8. A process for preparing an isobutene homopolymer having a weight-average molecular weight of 75,000 to 10,000,000, comprising:
(a) polymerizing isobutene with a conversion of 85 to 100% of isobutene in a polymerization reactor in the liquid phase in an inert solvent in the presence of a Lewis acid polymerization catalyst at a temperature of −140° C. to −190° C., to form the isobutene homopolymer,
(b) wherein the inert solvent is one or more C 1 to C 8 hydrocarbons, one or more halogenated C 1 to C 8 hydrocarbons or a mixture thereof, and
(c) wherein the Lewis acid polymerization catalyst is a complex of boron trifluoride and a C 1 - to C 4 -alkanol,
(d) wherein the polymerizing is carried out in the presence of at least one aldehyde reaction accelerator, and
(e) wherein the polymerizing is carried out in the presence of diisobutene as a chain length regulator,
discharging the isobutene homopolymer formed by the polymerizing from the polymerization reactor at a temperature of less than −80° C.,
thermally purifying the isobutene homopolymer formed by the polymerizing with one or more extruders at a temperature of more than +80° C.;
wherein during the thermally purifying an inert gas which is different from the inert solvent is introduced into one or more segments of the one or more extruders.

9. The process according to claim 8 , wherein the polymerizing is carried out at a temperature of −160° C. to −185° C.

10. The process according to claim 8 , wherein the polymerizing includes cooling a polymerization medium comprising the isobutene and the inert solvent to a temperature of −140° C. to −190° C. and maintaining the temperature during the polymerizing with a separate cooling circuit.

11. The process according to claim 8 , wherein the inert solvent is at least one selected from the group consisting of ethane, ethene, propane, propene, n-butane, isobutane and a mixture thereof.

12. The process according to claim 8 , wherein the inert solvent is at least one selected from the group consisting of 1,1,1,2,3,3,3-heptafluoropropane, octafluoropropane and a mixture thereof.

13. The process of claim 1 , wherein the polymerization in (c) is a complex of boron trifluoride and at least one of methanol and isobutanol.

14. The process of claim 1 , wherein the aldehyde reaction accelerator is formaldehyde.

15. The process of claim 8 , wherein the Lewis acid polymerization catalyst is a complex of boron trifluoride and at least one of methanol and isobutanol.

16. The process of claim 8 , wherein the aldehyde reaction accelerator is formaldehyde.

17. The process of claim 1 , wherein the polymerization in (c) is carried out with a polymerization catalyst that is free of ether.

Assignees

• Basf Se

Inventors

• Wettling Thomas
• Hirsch Stefan
• Brym Markus
• Weis Markus
• Corberan Roc Rosa
• Muehlbach Klaus
• Haschick Robert
• Daiss Andreas
• Volland Marco-Christian

Classifications

• C08F110/10 Primary

  Isobutene · CPC title

• C08F4/70

  Iron group metals, platinum group metals or compounds thereof · CPC title

• C08F2500/04

  Broad molecular weight distribution, i.e. Mw/Mn > 6 · CPC title

• C08F4/52 Primary

  selected from boron, aluminium, gallium, indium, thallium or rare earths (C08F4/14 takes precedence) · CPC title

• C08F2500/01

  High molecular weight, e.g. >800,000 Da. · CPC title