Method for oligomerization of ethylene

Abstract

The invention discloses a method for oligomerization of ethylene. The ethylene is subjected to oligomerization in a reaction system containing a primary catalyst, an aluminum-containing cocatalyst, water and an organic solvent, wherein the primary catalyst is a complex of 2-acetyl-1,10-phenanthroline (2,6-diisopropylanil)FeCl2, the formula (I) of the complex is as shown in the specification, the organic solvent is the alpha-olefin of Cn (n is more than 4 and less than or equal to 10), and in the chemical formula, R1-R5 are independently selected from hydrogen, C1-C6 alkyl, halogen, C1-C6 alkoxy and nitryl. The method disclosed by the invention has the advantages that the technical prejudice can be overcome, the process for oligomerization of ethylene can be optimized, the ethylene has high oligomerization activity, the oligomerization of ethylene can be initiated rapidly and operated stably and is hypo-toxic and environment-friendly, the catalytic effect and the production cost can be comprehensively considered and well balanced and the oligomerization cost of ethylene can be reduced greatly. In addition, the method disclosed by the invention is highly practical and has a broad industrial prospect.

Description

technical field [0001] The invention relates to the field of olefin polymerization, in particular to a method for ethylene oligomerization. Background technique [0002] Linear α-olefins are widely used in the fields of ethylene comonomers, surfactant synthesis intermediates, plasticizer alcohols, synthetic lubricating oils and oil additives. In recent years, with the continuous development of the polyolefin industry, the worldwide demand for α-olefins has grown rapidly. At present, the vast majority of α-olefins are prepared by ethylene oligomerization. The used catalyst of ethylene oligomerization mainly contains nickel series, chromium series, zirconium series and aluminum series etc., in recent years, Brookhart group (Brookhart, the people such as M, J.Am.Chem.Soc.,1998,120,7143-7144 ; WO99 / 02472,1999), Gibson group (Gibson, V.C. et al., Chem.Commun., 1998,849-850; Chem.Eur.J., 2000,2221-2231) found that some Fe(II) and Co The tridentate pyridine imine complex of (II)...

AI Technical Summary

Problems solved by technology

Whether it is methylalumoxane or modified methylalumoxane, the unit price is relatively high, and when it is used for ethylene oligomerization on a large scale, it will inevitably lead to high production costs

At present, it is generally believed that water is very unfavorable to the ethylene oligomerization process

In addition, the oligomerization reaction has very strict requirements on the initiation environment, and it is strictly required to be carried out in an anhydrous and oxygen-free environment. Due to the special conditions, it is very difficult to achieve, so the reaction initiation, stability and repeatability of the oligomerization process are also very poor.

In addition, the organic solvent used in the oligomerization process is generally toluene. As we all know, toluene is a toxic aromatic hydrocarbon, which is irritating to the skin and mucous membranes and has an anesthetic effect on the central nervous system; and in the oligomerization products, the toluene content is relatively large , unable to meet the requirements for aromatic hydrocarbon content when used as a comonomer

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