An olefin polymerization catalyst system and its application

Abstract

The invention relates to the field of olefin polymerization, and discloses a catalyst system. The catalyst system comprises a titaniferous solid catalyst component, an aluminum alkyl compound and an external electron donor compound, wherein the titaniferous solid catalyst component contains at least two internal electron donor compounds of a polytrimethylene terephthalate type compound and a diether type compound, and the external electron donor compound is an ether base ester compound or a combination of the ether base ester compound and hydroxyl silane dialkyl oxygen radicals. The invention further provides application of the catalyst in olefin polymerization reaction. According to the catalyst system and the application of the catalyst in the olefin polymerization reaction, by adding the ether base ester compound or the combination of the ether base ester compound and the hydroxyl silane dialkyl oxygen radicals as the external electron donors to be used in the olefin polymerization reaction when the solid catalyst component with the polytrimethylene terephthalate type compound and the diether type compound being the internal electron donors is subjected to the olefin polymerization reaction, not only can the catalyst maintain high activity, but also sensibility of hydrogen regulation of the catalyst can be improved.

Description

technical field

[0001] The invention relates to the field of olefin polymerization, in particular, the invention relates to a catalyst system and its application in olefin polymerization. Background technique

[0002] As we all know, the catalyst system used in the homopolymerization or copolymerization of α-olefins generally consists of three parts, which are: (1) main catalyst (solid catalyst), (2) cocatalyst (usually alkyl aluminum compounds) and (3) an external electron donor compound added during polymerization.

[0003] The use of one or several external electron donor compounds to control the stereoregularity and morphology of polymers during polymerization is well known to those skilled in the art. In addition to affecting the stereoregularity of the polymer, the external electron donor often affects other aspects of the performance of the catalyst to varying degrees. Although many compounds are known to act as external electron donors, the use of different externa...

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