Catalyst based on rare earth metal compounds
AssigneeBayer Aktiengesellschaft
InventorsThomas Knauf, Wilfried Braubach
Life of this patent
Estimating the term…
Abstract
The present invention comprises a catalyst based on rare earth metal compounds which consists of a rare earth metal compound, an organic aluminum compound and a trihalosilane, of a process for the production thereof and of the use of the catalyst for polymerizing conjugated dienes to form high molecular weight polybutadienes.
Claims19
A catalyst based on rare earth metal compounds which comprises:
- a) a rare earth metal compound,
- b) an organic aluminum compound and
- c) a trihalosilane of the formula
- wherein
- Hal represents fluorine, chlorine or bromine and
- R represents hydrogen or a vinyl group,
- in which components a):b):c) are present in a ratio by weight of 1:0.5-5:0.05-0.5, wherein said rare earth metal compound is soluble in hydrocarbons, and wherein said catalyst does not include a silicon tetrahalide.
A catalyst according to claim 2, wherein said rare earth metal compound is a rare earth metal salt.
A process for the production of the catalyst based on rare earth metal compounds comprising the step of bringing into contact a rare earth metal compound (a) with an organic aluminum compound (b) and a trihalosilyl compound (c) at temperatures of −30 to 100° C., wherein components a):b):c) are used in a weight ratio of (1):(0.5-5):(0.05-0.5), wherein said rare earth metal compound is soluble in hydrocarbons, and wherein said catalyst does not include a silicon tetrahalide.
A process for producing polydienes comprising the step of polymerizing conjugated dienes in the presence of a solvent with a catalyst based on rare earth metal compounds which comprises:
- a) a rare earth metal compound,
- b) an organic aluminum compound and
- c) a trihalosilane of the formula
- wherein
- Hal represents fluorine, chlorine or bromine and
- R represents hydrogen or a vinyl group,
- in which component a):b):c) are present in a ratio by weight of 1:0.5-5:0.05-0.5, wherein said rare earth metal compound is soluble in hydrocarbons, and wherein said catalyst does not include a silicon tetrahalide.
Dependencies are inferred from the claim text.