| 摘要 |
Trialkylaluminium compounds are prepared by chain growing ethylene molecules on the alkyl groups of a tri-lower alkylaluminium compound feed, separating the formed mixed trialkylaluminium compound stream into the desired tri-higher alkylaluminium compound fraction and a tri-lower alkylaluminium compound fraction by a solvent extraction process, and recycling at least a portion of the tri-lower fraction to the chain growth step. The growth reaction product may be contacted at e.g. 14-104 DEG F. and 200 p.s.i.g. in a packed or rotating disc column with a solvent, such as a haloalkane containing at least one fluorine atom, with which the alkylaluminium compounds are only partially miscible, to yield a solution enriched in the lower alkyl components. These are separated by distillation and recycled to the chain growth step and the solvent, with make-up solvent returned to the extraction step. The higher alkyl components in the residue is fractionated from components of very long chain length and excess ethylene. Alternatively, the components of the chain growth product may be distributed between two partially miscible solvents, for example a haloalkyl ether, di-lower alkyl ether of a glycol or of a polyglycol as first solvent, and a saturated alkane having 3 to 22 carbon atoms as a second solvent. The first and second solvents dissolve fractions enriched in lower and higher alkyl aluminium compounds respectively, and these are fractionated in vaporizers, the solvents, with make-up solvent, being returned to the extraction step, the lower alkyl fraction to the chain growth step and the higher alkyl fraction recovered as the desired product.
|
