Preparation method of high-impact transparent polypropylene resin

Abstract

The invention belongs to the field of high-end novel materials, and discloses a preparation method of high-impact transparent polypropylene resin. According to the method, by adjusting the addition amount of ethylene in a loop reactor R201 / R202, the content of a random copolymer in a polymer is increased, the crystalline phase density of a product is reduced, and a crystalline phase and a non-crystalline phase have a similar refractive index, so the transparency of the product is improved; a polymerization reaction is continuously carried out in a gas-phase copolymerization kettle, a certain amount of ethylene is added to adjust the ratio of gas-phase composition C2<-> / (C2<->+C3<->) so as to improve the impact property of the product; and in the granulation molding stage of the product, acompound additive is added, so the crystal nucleus of the product is reduced, crystal nucleus density is increased, a crystallization rate is increased, crystallinity is increased, the haze of the product is reduced, and the rigidity of the product is improved.

Description

technical field [0001] The invention belongs to the field of high-end new materials and relates to a preparation method of polypropylene resin. Background technique [0002] Polypropylene is a widely used thermoplastic resin. It combines excellent mechanical properties and low cost. It has good non-toxicity and chemical corrosion resistance. It has broad market prospects and has become the fastest growing among the five general-purpose synthetic resins. The most active breed. In recent years, with the rapid development of coal-to-olefin and propane dehydrogenation technologies, the total output of polypropylene in my country has increased significantly. my country has become the world's largest polypropylene consumer, accounting for 30% of global consumption. Through market research, it is found that the annual demand for transparent polypropylene in the country is as high as 1 million tons, and most of the products are random transparent polypropylene. Due to its own char...

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Problems solved by technology

[0009] In order to solve the problems of low normal temperature impact strength of polypropylene resin products, poor transparency of ethylene-propylene block copolymers, complicated polymerization process and relatively difficult operation, the present invention provides a preparation method of high-impact transparent polypropylene resin, which increases product transparency Performance, improve the impact performance and rigidity of the product

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