Polymerization of ethylene catalyst component having high output ratio, preparation and use

Abstract

The invention relates to a catalyst component used for the ethylene polymerization or the co-polymerization, the preparation method thereof, and the application of catalyst comprising the catalyst component in the ethylene polymerization or co-polymerization. The catalyst component is formed by loading at least one inorganic titanium compound, at least one organic compound, at least one electron donor, and at least one activator on a magnesium / titanium-containing solid. The invention provides a high-efficiency high-hydrogen-sensitivity solid catalyst component capable of acquiring low fine powder content polymer. The catalyst component has the advantages of relatively narrow particle size distribution, smaller average particle size, and higher catalyst activity, and is suitable for the slurry polymerization or gas phase polymerization of ethylene, and particularly suitable for a gas phase fluidized bed polymerization process of ethylene by feeding the catalyst in the form of slurry. Meanwhile, the catalyst component has higher input-output ratio. The preparation method is low in cost and suitable for larger scale extension production.

Description

technical field [0001] The invention relates to a solid catalyst component for ethylene polymerization or copolymerization, a preparation method and the application in ethylene polymerization or copolymerization after the catalyst is composed. technical background [0002] In the polymerization or copolymerization of ethylene, 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 shape and particle size distribution of the catalyst particles are more suitable for the operation in a fluidized state, the above-mentioned catalyst components are usually supported on a carrier such as silica gel. For example: the catalysts disclosed in US4,302,565, US4,379,759 and CN1064870A are used for gas-phase fluidized bed reactions, which impregnate the matrix components prepared by titanium compounds, magnesium compounds...

AI Technical Summary

Problems solved by technology

[0003] In the above-mentioned published patents, in order to make the catalyst applicable to the gas-phase fluidized bed polymerization process, there are strict requirements on the average particle size, specific surface area and pore size of the carrier-silica used, and the carrier is relatively expensive. It needs to be strictly activated before use, which all lead to an increase in the production cost of the catalyst; and the active components of the catalyst are loaded on the carrier by impregnation and other methods, and the catalyst efficiency is not high due to the limitation of the amount of titanium loaded. people are satisfied

In addition, the content of polyethylene fine powder produced by using this catalyst is relatively large, usually fine powder below 150 microns accounts for about 15wt%, which is very undesirable in industrial production

When the catalyst is applied to the industrial equipment of ethylene gas-phase fluidized bed polymerization, the catalyst is mostly fed in the form of solid, and the feeding method is not stable, and it is prone to pipe plugging and bridging.

[0004] The catalyst production method mentioned in CN 1085915A, although overcome some shortcomings mentioned above, but need to use metal magnesium as reducing agent, and still need to use a large amount of silicon dioxide as carrier, also will adopt spray-dried The catalyst product is obtained by the method, the equipment investment is large and the operation is complicated, so that the overall production cost is still relatively high

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

[0006] Chinese patent CN1229092A discloses a catalyst for ethylene polymerization or copolymerization, which is formed by dissolving magnesium halide in organic epoxy compounds and organic phosphorus compounds and adding electron donor activators to form a homogeneous solution. Precipitating agent and halide of transition metal titanium and its derivatives, the catalyst showed high activity when used in the slurry polymerization of ethylene, but the catalyst component added with alcohol activator was used In the gas phase polymerization process of ethylene, especially in the fluidized bed polymerization process, especially in the initial stage of the polymerization reaction, the polymerization reaction is fast, so that the generated polymer is easily broken, and the polymer particles are relatively fine, with a particle size of 70-150 microns. Particles account for 50Wt% to 60Wt%, and the shape regularity of the polymer is not good, the result is not satisfactory