Preparation method of high impact co-polypropylene

Abstract

Belonging to the field of olefin polymerization in the petrochemical industry, the invention discloses a preparation method of high impact co-polypropylene. Specifically, carboxylate superfine powder particles are added into a vapor phase polymerization kettle to replace the existing LPN system. The preparation process is simple and practicable, compared with the prior art, the method provided by the invention can be applied to acquire a high impact ethylene co-polypropylene product, and also the method can maintain long-period stable operation of the production device.

Description

technical field [0001] The invention relates to olefin polymerization in petrochemical industry, a process technology for preparing high-impact copolymerized polypropylene under propylene gas phase polymerization process or bulk gas phase combined process. Background technique [0002] Polypropylene is a typical partially crystalline thermoplastic resin, and its good performance-price ratio determines that it has a wide range of applications. In recent years, with the rapid development of the automobile industry, high-speed trains, construction industry, electronic telecommunications industry and the high performance of polypropylene products, the output and demand of polypropylene have increased significantly, becoming the fastest growing general-purpose plastic in the past ten years. Annual demand growth of up to 8%. With the development and application of production technology and new catalysts, many high-performance polypropylene products appear in the market, mainly in...

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Problems solved by technology

[0006] 1) With the addition of a large amount of LPN, a large amount of inert gas accumulates, which reduces the partial pressure of monomers effectively participating in the polymerization, resulting in a decrease in polymerization production efficiency. Roughly estimated, the partial pressure is about 50% when the nitrogen gas is balanced, that is, compared to no nitrogen gas, Polymerization production efficiency drops by at least 50%;

[0007] 2) Excessive nitrogen increases the discharge frequency of the gas phase kettle, increases the amount of post-treatment separation, and increases production costs. If it is directly emptied, the unit consumption of the product will increase significantly

In addition, the application of inorganic particles is mainly in post-processing modification. For example, CN1307074A and CN1150161 propose to use nanoparticles to strengthen and toughen polypropylene materials. This process requires secondary melting of polymers, and the dispersion of inorganic particles is difficult, which increases the cost of product manufacturing.

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