Process for continuously producing co-polypropylene with high ethylene content by using propylene gas-phase polymerization device

Abstract

The invention provides a process for producing co-polypropylene with high ethylene content by using a device for producing polypropylene by a horizontal gas-phase stirring bed. The process is characterized by comprising the following steps of: continuously feeding gas-phase propylene and a catalyst into a first reaction kettle A to perform gas-phase polymerization; making the powdered materials fall into a gas locking device B after the propylene is polymerized; storing ultrathin powder into an ultrathin inorganic powder storage tank D; quantitatively adding the ultrathin powder into the gas locking device B through an ultrathin inorganic powder conveying device E, making the ultrathin inorganic powder and the polypropylene powder, which are in an amount of 0.01 to 10 percent of the totalweight of the polymer, fall into a second reaction kettle B; feeding ethylene and propylene into the second reaction kettle B to perform copolymerization on ethylene and propylene; finally making a polymerized product fall into a material house, and discharging the product and packaging the product. By employing the process and combining the characteristics of the propylene gas-phase polymerization device, the copolymerized product with good property and stable quality can be produced, can continuously work for 720 hours to increase the market competitiveness of the product, and has giant economic benefit and social benefit.

Description

technical field [0001] The invention relates to a method for continuously and stably producing ethylene-propylene copolymerized polypropylene in a propylene gas phase polymerization process, especially the preparation of copolymerized polypropylene with high ethylene content and ultra-high ethylene content. 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 production and demand of polypropylene have increased significantly, becoming the fastest growing general-purpose plastic in the past 10 years. , the annual demand growth rate is as high as 8%. With the improvement of production technology and the development and application of ...

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Problems solved by technology

CN1307074A, CN1150161 also disclose the preparation method of similar nanoparticle reinforced and toughened polypropylene material, this kind of method is limited to the post-processing modification technology of polypropylene at present, needs to go through secondary melting and extruding, and the dispersion of inorganic particles is relatively uniform. Difficult, material manufacturing cost also increases

CN1289786A discloses a method for preparing polyolefin composite materials by intercalation composite method, which is to carry out olefin polymerization directly after complexing montmorillonite and polyolefin catalyst, this method can realize the uniform dispersion of inorganic particles in the polymerization product, The interface between inorganic and organic substances is strongly combined, but this type of polymerization is currently limited to a few polar polymers such as polyester and polyamide, and no reports of large-scale production have been found.

Therefore, the dosage of low-purity nitrogen is particularly critical. If the dosage is small, the polymer particles tend to form sticky lumps. If the dosage is large, it will diffuse into the catalyst to accelerate the reduction of catalyst activity, affect the ratio of ethylene to propylene in the rubber in the copolymer, and then affect the performance of the product.

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