Late transition metal catalyst for ethylene oligomerization and preparation method thereof

Abstract

The invention provides a late transition metal catalyst for ethylene oligomerization and a preparation method thereof. The preparation method comprises the following steps: by using hyperbranched molecules using low generation terminal group as amido group and salicylaldehyde or salicylaldehyde derivatives as the raw materials in combination with anhydrous sodium sulfate and ethanol, carrying out reflux reaction under nitrogen conditions, and filtering to obtain a salicylaldehyde-Schiff base mixture; under nitrogen conditions, slowly and dropwisely adding a crystalline-water-bearing late transition metal halide ethanol solution into the salicylaldehyde-Schiff base mixture to react; and filtering and washing to obtain the late transition metal catalyst for ethylene oligomerization. The preparation method of the late transition metal catalyst for ethylene oligomerization prepared by the one-pot process is simple, and avoids the complex process of purifying the ligand in the conventional late transition metal catalyst for ethylene oligomerization; and the catalyst yield is 80-90%. The catalyst has higher catalytic ethylene oligomerization activity, and can easily implement industrial production.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and relates to a post-transition metal catalyst for ethylene oligomerization and a preparation method thereof. Background technique [0002] Late transition metal catalysts are a new generation of olefin polymerization catalysts that appeared in the 1990s with high activity for olefin polymerization. The catalyst can realize the catalytic polymerization of polar monomers and the copolymerization of polar monomers and non-polar monomers, and can also obtain high molecular weight polyethylene, poly alpha-olefins and alpha-olefins. Compared with metallocene catalysts, the catalytic activity of late transition metal catalysts is higher than that of metallocene catalysts. The molecular weight and branching degree of polymerization products can be adjusted and controlled. The catalyst is cheap, stable in performance, easy to prepare, and can simplify the production rate of the synthesis process. Hig...

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Problems solved by technology

However, the synthesis steps are long, and the catalyst ligands need to be purified, the overall yield is low, and it is difficult to realize industrial production

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