Industrial production method of high isotactic polybutylene and device for implementing method

Abstract

The invention discloses an industrial production method of high isotactic polybutylene and a device for implementing the method. The production method comprises the process flows of carrying out bulk polymerization on a liquid-phase butylene-1 monomer in a polymerization kettle at the temperature of 10 DEG C below zero to 70 DEG C above zero to synthesize isotactic polybutylene, and recovering part of unreacted butylene-1 into a butylene gasometer through primary pressure reduction after polymerizing for a certain period of time; then, transferring high isotactic polybutylene from the polymerization kettle to a flash distillation kettle, carrying out reduced-pressure flash distillation, and further recovering the unreacted butylene-1 monomer into the butylene gasometer; sequentially introducing nitrogen gas and air into the flash distillation kettle to replace, discharging a granular high isotactic polybutylene product through an emptying valve at the bottom of the kettle, and packaging. The device comprises a proportioning system, a polymerization system, a gas distribution system, a vacuum nitrogen system, a degassing and flash distillation system and a utility system. Through the industrial production method and the device, the industrial synthesis of the high isotactic polybutylene can be realized, and no organic solvents, waste gases, waste water and waste residues are discharged; in addition, the industrial production method belongs to a green and clean production process.

Description

technical field [0001] The present invention relates to the field of petrochemical industry, in particular to a method for producing high isotactic polybutene, and more specifically to an industrial production method and device for preparing high isotactic polybutene by liquid-phase bulk polymerization. Background technique [0002] High isotactic polybutene is a semi-crystalline polymer obtained by polymerization of butene-1 monomer. Its main physical and mechanical properties are similar to those of current general-purpose polypropylene and polyethylene. Alternative use in ethylene and polypropylene applications. [0003] High isotactic polybutene has outstanding thermal creep resistance (Vicat softening temperature is about 20°C higher than that of polypropylene), excellent impact resistance and lower glass transition temperature, so that it can be used at -20°C~ Use for a long time between 110°C. The use of high isotactic polybutene homopolymers and copolymers is mainl...

AI Technical Summary

Problems solved by technology

The biggest disadvantage of gas-phase polymerization is: low monomer concentration and partial pressure (inert gas with a boiling point lower than butene monomer often exists in gas-phase polymerization, which is used to reduce and avoid polymer bonding and to be brought by the volatilization of inert low-boiling gas. take the heat of polymerization), the polymerization rate is relatively low; the requirements for the polymerization process, polymerization device and process operation are very high, usually only large-scale enterprises can realize it, and it is not suitable for general small and medium-sized enterprises, especially some small-sized polypropylene devices for transformation. ene polymerization

In solution polymerization, polybutene swells and dissolves in its monomers, which makes the system sticky, resulting in difficulties in mass transfer and heat transfer, which limits the polymerization process to be terminated at low conversion rates or to use reactive extrusion Technology to further increase the conversion rate and remove unreacted monomers

In this way, the production efficiency is reduced, while the complexity of the production process and the production cost increase

Chinese invention patent 200710013587.X prepared polybutene with high identity by bulk precipitation method, which overcomes the shortcomings of solvent recovery and post-treatment in solution method, but this patent only covers the synthesis method of polybutene by bulk precipitation polymerization and the material itself It is protected and does not involve the production method, process flow and implementation equipment of industrial production; in the preparation method disclosed in this patent, the monomers that do not participate in the polymerization reaction are recovered through a flash evaporation, and the monomer recovery is incomplete, resulting in waste; The patent only mentions supported TiCl prepared by milling method 4 The main catalyst; the patent does not mention the post-treatment of the polymer. During the polymer packaging process, if the polymerization system is opened, the residual monomers in the polymer that are not fully recovered will volatilize and leak in the polymerization workshop. If it is higher, there will be a potential explosion hazard, which will not only affect the production and equipment, but also endanger the staff; this patent has not considered the potential risk that the recycled monomer cannot enter the polymerization system in case of emergency failure At the same time, the patent does not mention the purification of recovered monomers. Inert impurities and reactive impurities in recovered monomers are introduced into the polymerization system, which will seriously affect the normal implementation of polymerization production, reduce production efficiency, and reduce product quality.

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