Gas phase fluidized bed process LLDPE catalyst, preparation and application thereof

Abstract

The invention relates to a catalyst for preparation of LLDPE by a gas phase fluidized bed process, preparation and application thereof. The catalyst takes porous silica gel and anhydrous magnesium chloride as the carrier, adopts a titanium-containing transition metal loaded on the porous silica gel-magnesium chloride composite carrier as active components, and employs an electron donor compound as a modifier. In terms of the total mass of the catalyst, the load components include: 1.00-5.00% of Ti, 15.20-32.35% of Cl, 1.35-6.52% of Mg, 0.10-5.78% of the electron donor, and the balance silica gel. The catalyst is used for a gas phase polyethylene process, solves the problems of low activity, poor copolymerization ability and high product ash content in general catalysts, and can be used for production of polyethylene resin with different melt indexes, especially for production of ethylene / 1-hexene copolymerization new products with high added value, thereby enhancing the product performance, improving the processability of resin, and broadening the application fields of the products.

Description

technical field [0001] The present invention relates to a catalyst for preparing LLDPE by gas-phase fluidized bed method and its preparation method, and the application of the catalyst in ethylene gas-phase polymerization or copolymerization, especially in ethylene gas-phase fluidized-bed polymerization condensed state or super-condensed state polymerization application. Background technique [0002] The gas-phase polyethylene process is an advanced polyethylene production process. There are many sets of equipment in the world that use the gas-phase process to produce polyethylene. At present, the titanium-based Ziegler-Natta catalyst is the main catalyst for the production of polyethylene, and the linear low-density polyethylene produced by the catalyst has good processability and mechanical properties. The catalyst suitable for the gas phase fluidized bed polyethylene process should have good fluidity and certain mechanical strength, and its shape should be spherical or q...

AI Technical Summary

Problems solved by technology

[0005] In the above-mentioned dry powder catalyst method, all have to undergo alkylaluminum reduction treatment, and when using this type of catalyst to produce linear low density polyethylene with a high melt index, there is a high content of fine powder, and the polymer is prone to static electricity in the reactor, forming Sheeting is not conducive to the smooth operation of production equipment

In addition, the hydrogen adjustment sensitivity and copolymerization ability of such catalysts are generally poor, especially the poor copolymerization ability with 1-hexene or 1-octene, which is not conducive to the production of new high value-added polyethylene products

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