Catalyst composition suitable for homopolymerization or copolymerization of propylene

Abstract

The present invention provides a catalyst composition suitable for homopolymerization or copolymerization of propylene, the catalyst composition comprising: one or more Ziegler-Natta procatalyst compositions, the Ziegler-Natta procatalyst composition The material includes magnesium, titanium and one or more internal electron donors, and the internal electron donor is a Lewis base containing one or more electronegative groups, and the atoms of the electronegative groups are selected from N, O, The group consisting of S, P, As or Sn; one or more cocatalysts comprising aluminum; one or more silicon-containing external electron donor compounds (ED); and one or more active stabilizer compounds ( TD), the active stabilizer compound is at least one citrate compound selected from the general formula (I). The catalyst composition can reduce the fluctuation of the reaction temperature in the reactor and reduce the hot spots of the reactor and polymer agglomeration while maintaining the activity level of the catalyst through the addition of the activity stabilizer.

Description

technical field [0001] The invention relates to a catalyst composition suitable for the homopolymerization or copolymerization of propylene, in particular to a catalyst composition for the polymerization of propylene or a mixture of propylene and one or more copolymerizable comonomers and its polymerization application. Background technique [0002] Ziegler-Natta catalyst compositions known in the art mainly consist of a procatalyst and a cocatalyst. The main catalyst is synthesized by loading titanium compounds on the carrier (active magnesium halide carrier is the most common). In order to improve the activity and stereoselectivity of the catalyst, it is necessary to add electron donor compounds during the synthesis of the catalyst and the polymerization of propylene, respectively called Internal electron donor (ID) and external electron donor (ED); the cocatalyst is an organometallic compound, usually an organoaluminum compound. [0003] The role of the external electro...

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Problems solved by technology

[0006] In order to further adjust the properties of the polymer and improve the problems encountered in the polymerization such as large temperature fluctuations, unstable reaction, and polymer agglomeration, the present invention provides a catalyst composition containing an active stabilizer, which can effectively improve the stability of the polymerization reaction, Reduce reaction temperature fluctuations and hot spots, reducing polymer agglomeration while maintaining or even increasing catalyst activity levels

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