Polymerizing process for improving flowability of copolypropylene powder

Abstract

A polymerizing process for improving the flowability of copolypropylene powder features that the Z-N type Ti-series polypropylene catalyst system is used in the multi-phase block polymerization of polypropylene, the superfine inorganic material, said catalyst system, the trialkyl aluminium (triethyl aluminium or aluminium diethylchloride) as co-catalyst, and the alkoxyl silane as electron provider are used, and the mechanical stirring is combined with ultrasonic for uniformly dispersing said inorganic material chosen from saperfine talc powder and superfine calcium carbonate.

Description

(1) Technical field [0001] The present invention relates to the improvement of the polymerization method of copolymerized polypropylene, in particular to the polymerization method for improving the flowability of the copolymerized polypropylene powder. (2) Background technology [0002] Isotactic polypropylene (IPP) has the advantages of high melting point, high rigidity, and good processability, but its high glass transition temperature (about 0°C) and low impact strength limit its application fields. In order to broaden the application of PP, it is expected to have moderate softness, high transparency and good low temperature impact resistance. This kind of PP can only be obtained by copolymerization, and random copolymerization and heterogeneous block copolymerization (commonly known as block copolymerization) of propylene and ethylene are widely used in industry to prepare random copolymerized PP and block copolymerized PP. However, no matter when Himont production proc...

AI Technical Summary

Problems solved by technology

At present, when the domestic Himont and Hypol production processes are used to produce multi-block copolymers, a small amount of substances harmful to the activity of the polymer are often used as surface passivators in the gas phase reactor, such as low-purity nitrogen containing oxygen and other organic substances. , so that the activity of the surface of the polymer particles is deactivated, and the surface of the particles cannot generate ethylene-propylene copolymerized substances. This method will affect the activity of the catalyst and reduce the production volume when producing copolymers. At the same time, the added metering and catalyst activity life The long-term relationship is unstable, which will also cause fluctuations in production and product performance

Or add surface-modified general inorganic powder materials into the gas-phase polymerization kettle, but its addition is large, and it cannot be used for random copolymerization of liquid-phase bulk