Amine-bridged triphenol tetradentate ligand subgroup IV metal complex and application

Abstract

The invention relates to an amine-bridged triphenol tetradentate ligand subgroup IV metal complex and application and belongs to the technical field of olefin polymerization catalysts. The complex herein has a structural general formula which is shown in the description. With a mixture of a boron agent with alkylaluminoxane, alkyl aluminum halide or aluminum alkyl serving as a cocatalyst, the complex herein can be used as a main catalyst to catalyze olefin polymerization. The preparation process of the ligand and complex herein is simple, and the yield is high; when the complex herein is usedas a catalyst, the complex has high resistance to a cocatalyst and impurities and has the advantages of good stability, long catalytic life, good thermal stability, high catalytic activity and the like; the complex herein can be used to catalyze olefin polymerization to attain ultrahigh molecular weight polyethylene.

Description

technical field [0001] The invention belongs to the technical field of olefin polymerization catalysts, and in particular relates to a [ONOO] type tetradentate fourth subgroup metal complex with three phenolic compounds bridged by an amine and its application in catalyzing ethylene polymerization. Background technique [0002] Polyolefin products have become the most popular resin materials because of their rich raw materials, low price, convenient production and processing, and superior performance. The polyolefin industry represents the development level of a country's petrochemical industry. An important part of the national economy and national defense strategy. Olefin polymerization catalyst determines the internal structure and morphology of polyolefin products. It is the core technology in the development of polyolefin industry. Its development generally goes through three stages: a). Ziegler-Natta catalyst, which is the earliest olefin polymerization catalyst , its ...

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Problems solved by technology

[0003] The background technology closest to the present invention is: a catalyst disclosed in the article Chem.Commun., 2011,47,12328-12330 published by British scientist Jones, but the catalyst of this structure cannot catalyze olefin polymerization, generally only Used to catalyze the ring-opening polymerization of compounds such as lactide

Japanese scientist Nomura synthesized a series of alkoxy compounds of titanium and zirconium by using nitrogen atoms bridged with three benzylphenol compounds as ligands. This type of compound is the same as the former, and cannot catalyze olefin polymerization when used directly. The modification of alkylaluminum, and under the secondary activation of MAO, can barely catalyze ethylene polymerization; however, such catalysts generally use small groups such as methyl as substituents, and the largest substituent is only tert-butyl. During polymerization, effective space protection for the metal active center cannot be formed, and it is easily deactivated by alkylaluminums, and the catalytic life is short; in terms of catalyst structure, the center metal of this type of catalyst is surrounded by a symmetrical structure of three six-membered rings, which is not conducive to The co-catalyst effectively activates the metal active center, so the polymerization activity is very low. The activity of the synthesized series of catalysts to catalyze ethylene polymerization is only 7570kgPE / (molCatalyst h); when the catalyst is synthesized, the raw material cost is high, the steps are complicated, and the modification is difficult , the synthesis conditions are more harsh; when used, the amount of co-catalyst required is very large, and the use of alkylaluminum and a large amount of MAO is required to show catalytic activity

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