Production technology of the hottest analytic tran

2022-07-26
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Analysis of transparent polypropylene production technology

the spherulite of polypropylene (PP) is extremely fine and uniform through antireflection modification, which can significantly improve its gloss and transparency, and the Vicat softening point, crystallization temperature and rigidity are correspondingly improved. After PP is modified, its effect is equivalent to that of common transparent resins such as polystyrene (PS), polycarbonate (PC), polyester (PET) and polyvinyl chloride (PVC). Its application field can be extended to toys, packaging materials, medical machinery, industrial parts, etc

in 2013, the consumption of transparent polypropylene in China was about 700000 tons. In 2016, the consumption of transparent polypropylene increased to about 1.2 million tons. It is one of the PP types with rapid demand growth in recent years. At present, there is no polyolefin production enterprise involved in the coal chemical route, and the import source is mainly from South Korea

production technology of transparent PP

1. Using Z-N catalyst to produce random copolymerization transparent PP

the light transmittance of random copolymerization PP can exceed 94%, which is basically close to the transparency of PS. At present, more than 60% of the world's transparent PP production uses the 4th generation Z-N catalyst and the 3rd generation ultra-high activity Z-N catalyst, including ft-4s, gf-2a and udc-104 catalysts of HIMONT, tk- II catalyst of Mitsui Petrochemical Company, CD catalyst of Amoco company and SHAC catalyst of shell company. These catalysts not only have high directivity and high activity, but also can Comparing the size of each sample, controlling the particle morphology in polymerization has the characteristics of reactor particle technology, which is very beneficial to the production of random copolymerization high transparent PP. At present, most PP polymerization processes can use Z-N catalyst to directly produce random copolymerized transparent PP, such as Hypol bulk process, Spheripol bulk process, novolen gas phase process, Unipol gas phase process and BP Amoco gas phase process

2. Using metallocene catalyst to produce transparent pp

the crystallinity of the random copolymerization transparent PP decreases, and the rigidity of the formed products often decreases. In order to solve this problem, foreign companies have successfully developed a new metallocene catalyst. 6. The cement pressure testing machine is equipped with a color HP printer to control the polymerization of PP structurally. The isotactic PP obtained has very good transparency. The technologies include: univation (exxpol/unipol) technology of ExxonMobil company, Spheripol and metocene technology of Basell company, Unipol technology of dow/ucc company, borecene technology of Borealis company, and innovative ne technology of BP company with good flame retardancy. Metallocene catalyst technology can be used to produce isotactic transparent PP. At present, the transparency of PP prepared by Metallocene/single active site catalyst technology is the best

3. Adding nucleating agent to PP resin to improve the transparency of PP

adding transparent nucleating agent to common PP resin to achieve high performance and high transparency is the most commonly used and active modification method at present. Typical production companies of nucleating agent include merican, Nippon physicochemical Corporation, EC Chemical Corporation, Mitsui East Asia, and Shanxi Chemical Research Institute

4. Blending method plays a role in heterogeneous nucleation and crystal size reduction of PP antireflection modified blends. For example, blending PP, ethylene propylene diene monomer (EDPM) and low density polyethylene (LDPE) together can not only improve the transparency of PP, but also improve its impact resistance. In addition, compared with adding only rosin type nucleating agent, adding rosin type nucleating agent and a small amount of LDPE into PP resin can greatly improve the crystallization rate of PP when it is ready for painting. The obtained spherulites are not only smaller in size, but also more uniform in distribution, so the transparency of PP is further improved. However, there are some limitations in using blending method to improve the permeability of PP resin. Therefore, there are few studies on this method at present, and the development speed is relatively slow

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