Ethylene oligomerization method

Abstract

The present invention discloses an ethylene oligomerization method, wherein ethylene is subjected to an oligomerization reaction in a reaction system containing an isobutyryl substituted 1,10-phenanthroline aminal iron (II) complex coordination compound main catalyst represented by a formula (I), an aluminum-containing assisted catalyst, water and a solvent, and the solvent is alpha-olefin of Cn (n is more than 4 and is less than or equal to 10), wherein in the formula (I), R1-R5 are respectively and independently selected from hydrogen, C1-C6 alkyl, halogen, C1-C6 alkoxy and nitro. According to the present invention, the technical prejudice is overcome, the oligomerization process is optimized, the oligomerization activity is high, and advantages of rapid ethylene oligomerization reaction process initiation, stable operation, low toxicity, environmental protection, good catalytic effect and cost balancing, and strong practicality; and the ethylene oligomerization reaction cost is substantially reduced, the catalysis effect and the production cost are comprehensively considered, and the industrialization prospects are broad.

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)...

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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

And the oligomerization reaction is very harsh on the environment that initiates, it is generally believed that water is very unfavorable to the ethylene oligomerization reaction process

For example, CN200810111717.8 discloses a method for ethylene oligomerization, which is strictly controlled in an anhydrous and oxygen-free environment, resulting in very poor reaction initiation and repeatability of the oligomerization process.

In addition, the 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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