Catalyst component used in ethylene polymerization reaction, catalyst and preparation method thereof

Abstract

The invention discloses a catalyst component used in ethylene polymerization reaction, a preparation method of the catalyst component and a catalyst thereof. The catalyst component is formed by supporting at least one inorganic titanium compound, at least one organic titanium compound, at least one electron donor compound and at least one activating agent onto a solid substance containing magnesium / titanium. The solid substance containing magnesium / titanium is prepared by dissolving a magnesium compound in a solvent system containing an organic epoxy compound and an organic phosphorus compound to form a uniform solution, and performing co-precipitation to a titanium compound with one or more organic ester compounds in the presence of a composite precipitation aid. The catalyst component is narrow in particle distribution and is less in average particle size. The catalyst is high in activity and hydrogen regulation sensitivity and can be used for preparing low-fine-powder-content polymers.

Description

technical field [0001] The invention belongs to the field of olefin polymerization, and in particular relates to a catalyst component for ethylene homopolymerization and copolymerization, a preparation method of the catalyst component, a corresponding catalyst and its application in ethylene polymerization. Background technique [0002] In the polymerization of olefins, especially in the homopolymerization of ethylene or the copolymerization of ethylene and α-olefin, catalyst components with magnesium, titanium, halogen and electron donor as basic components are mostly used. When this type of catalyst is used in a gas-phase fluidized bed polymerization process, in order to ensure that the catalyst particle shape and particle size distribution are more suitable for fluidized state operation, the above catalyst components are usually supported on a carrier such as silica gel. For example: the catalyst disclosed in US4,302,565, US4,379,759 and CN1064870A for gas-phase fluidized...

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Problems solved by technology

[0004] And the catalyst production method mentioned in the Chinese patent whose publication number is CN1085915A needs to use metal magnesium as a reducing agent in the production process, and still needs to use a large amount of carbon dioxide Silicon is used as a carrier, and the catalyst particle product needs to be obtained by spray drying. The equipment investment is large and the operation is complicated, so that the overall production cost is still high

[0005] Chinese patent CN85100997 discloses a catalyst for olefin polymerization, which is formed by dissolving magnesium halide in organic epoxy compounds and organic phosphorus compounds to form a uniform solution, and then donating electrons with at least one precipitation aid and a polycarboxylic acid ester It is prepared by the action of the body and transition metal titanium halide and its derivatives. When the catalyst is used for the polymerization of propylene, it shows high polymerization activity and good stereospecificity, but when it is used for the polymerization of ethylene, the activity is low. Moreover, the particle size distribution of the polymer is relatively wide, and the hydrogen adjustment sensitivity of the catalyst is not good

When this catalyst component added with alcohol activator is used in ethylene gas phase polymerization process, especially in the fluidized bed polymerization process, especially in the initial stage of polymerization reaction, the polymerization reaction is faster, so that the generated polymer is easily broken, The polymer particles are relatively fine, and the particle size distribution of 70-150 microns accounts for 50Wt%-60Wt%, and the shape of the polymer particles is not good, and the result is not satisfactory

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