Catalyst composition used for olefin polymerization, and applications thereof

Abstract

The invention provides a catalyst composition used for olefin polymerization. The catalyst composition used for olefin polymerization comprises a solid catalyst ingredient a, an aluminium alkyl b, and an organic silicon compound c with a structure represented by general formula (I), wherein the organic silicon compound c is used as an external electron donor; the solid catalyst ingredient a comprises magnesium, titanium, halogen, and an internal electron donor, such as at least one selected from ethers and esters, wherein the internal electron donor contains ione pair electrons; the external electron donor c can be a diether compound with a structure represented by general formula (II) and a mixture of organosilanes with a structure represented by formula (I); and when the solid catalyst ingredient a is subjected to olefin polymerization with the presence of the external electron donor c, the solid catalyst ingredient a possesses high-temperature self-extinguishing capacity.

Description

technical field [0001] The invention belongs to the technical field of olefin polymerization catalysts, and relates to a catalyst composition for olefin polymerization and an application thereof. Background technique [0002] It is well known that solid titanium catalyst components based on magnesium, titanium, halogen and electron donors can be used in olefin polymerization, especially in the polymerization of α-olefins with 3 or more carbon atoms. Yield and higher isotactic polymers, in which the electron donor compound is one of the essential components in the catalyst component, and with the development of the internal electron donor compound, the polyolefin catalyst is constantly updated, and the external The electron donor also needs to be developed in conjunction with the internal electron donor. At present, a large number of electron donor compounds have been disclosed, such as internal electron donor monocarboxylic acid esters or polycarboxylic acid esters, ketones...

AI Technical Summary

Problems solved by technology

The external electron donor is used in conjunction with the existing solid catalyst to catalyze the polymerization of propylene, which can have high activity and orientation ability. However, when it is used in some occasions, especially in the gas phase process, the heat transfer is difficult due to the uneven dispersion of the gas medium. The effect is not as good as in the liquid medium, resulting in local hot spots in the polymerization process, and the catalyst still has high activity at high temperature, and then there will be implosion phenomenon

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