Process for the production of highly reactive polyisobutenes
View Patent ↗The present invention relates to a process for the production of highly reactive polyisobutenes with a content of terminal vinylidene groupings of greater than 80 mol % and an average molecular weight of 500 to 10,000 Dalton by cationic polymerization of isobutene or of isobutene and monomers copolymerizable with isobutene in the presence of solvent-stabilized transition metal complexes with weakly coordinated anions.
1. A process for the production of highly reactive isobutene homopolymers and copolymers with a content of terminal vinylidene groupings of greater than 80 mol % and an average molecular weight of 500 to 10,000 Dalton, comprising polymerizing an isobutene monomer or an isobutene and a copolymerizable monomer(s) in the presence of a transition metal catalyst of the general formula [M(R 1 -CN) 4-6 ](A) 2 , wherein
M is a metal from the 3rd to 12th periods of the periodic system of elements,
R 1 is a C 1 -C 8 alkyl group and
A is a weakly coordinating anion.
2. The process according to claim 1 , wherein the polymerization is performed at a temperature from 0 to 100° C.
3. The process according to claim 2 , wherein the polymerization is performed at a temperature from 20 to 60° C.
4. The process according to claim 1 , wherein the copolymerizable monomer is isoprene, styrene or a mixture thereof.
5. The process according to claim 1 , wherein the polymerization is in the presence of an inert organic solvent.
6. The process according to claim 1 , wherein the catalyst is introduced in a molar ratio of 1:15,000,000 to 1:10, relative to the total amount of monomer.
7. The process according to claim 1 , wherein M is Mn, Ni, Cr or Zn.
8. The process according to claim 1 , wherein A comprises anions of the formulae BF 4 − , SbX 6 − , PX 6 − , B(Ar) 4 − or B(Ar) 4 − anions bridged by cyclic groupings wherein Ar is a phenyl with 1 to 5 substituents.
9. The process according to claim 8 , wherein the substituent is Fl, Cl of CF 3 .
10. The process according to claim 1 , wherein R 1 is a C 1 -C 4 alkyl residue.
11. The process according to claim 1 , wherein R 1 is methyl, ethyl, propyl, butyl, isobutyl or tert-butyl.
12. The process according to claim 1 , wherein said average molecular weight is 2,000 to 7,000 Dalton.
13. The process according to claim 1 , wherein said content of terminal vinylidene groupings is 95 to 100 mol %.
14. The process according to claim 5 , wherein a concentration of monomers in said solvent is from 0.01 to 10 mol/l.
15. The process according to claim 1 , wherein said highly reactive isobutene homopolymers and copolymers have a PDI of from 1.2 to 1.8.
16. The process according to claim 1 , wherein said highly reactive isobutene homopolymers and copolymers have a content of incorporated isoprene of up to 60%.
17. The process according to claim 1 , wherein a concentration of introduced catalyst in the reaction mixture is in the range of from 0.01 to 10 mmol/l.
18. The process according to claim 1 , further comprising:
i) producing a polyisobutene/maleic anhydride adduct; and
ii) reacting said adduct with an amine.
19. The process according to claim 18 , wherein an additive for lubricants and/or fuels is produced.