Resource-saving preparation method of isoolefine and conjugated diene copolymer

Abstract

The invention relates to a resource-saving method for preparing an isoolefine and conjugated diene copolymer. The method comprises the steps as follows: an isoolefine monomer and a conjugated diene monomer, a solvent, a catalyzer and an accessory ingredient are put in an extrusion reactor, an unloading extruder and a postprocessing extruder system which are connected in three stages in series forcontinuous solution polymerization, termination, wash, devolatilization and post processing. The process units involved in the method are advanced; the process flow is short; the resource-saving method is very controllable; the resource-saving method significantly saves resources and investment compared with the traditional art; the total energy consumed is reduced by more than 50 percent; the product quality is stable; the production cycle is short; the environment is not polluted.

Description

technical field [0001] The invention relates to the field of preparing polymers, in particular to a resource-saving method for preparing isoolefin and conjugated diene copolymers. Background technique [0002] The main species of isoolefin and conjugated diene copolymer is isobutylene and isoprene copolymer (referred to as butyl rubber). Since the advent of butyl rubber, because of its low air permeability, good air tightness, heat aging resistance, deep Widely concerned by countries all over the world. Early butyl rubber production usually uses Friedel-Craft cationic catalysts, and industrial production is carried out in the polymerization solvent methyl chloride at a very low polymerization temperature (-100 ° C). Since butyl rubber is insoluble in methyl chloride, it forms a polymerization There are some disadvantages in this slurry production process, [0003] (1) The energy consumption in the manufacturing process is very large, mainly due to the huge energy consumpti...

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Problems solved by technology

[0004] (2) The equipment investment for industrial production of butyl rubber is very high. In addition to the cost of circulating cooling equipment accounting for 35% of the total investment, the reactor itself is also very expensive

[0005] (3) In the production of butyl rubber, the glue coating of the polymer will increase the temperature in the reactor, and it is difficult to ensure stable quality

First, the discharge screw is a single-screw extruder, which is prone to fouling and therefore cannot be operated continuously for long periods of time

Second, the liquid reaction solvent is forced back to the reactor by gravity rather than being removed from the material stream first, thereby not providing an opportunity to purify the liquid reaction solvent, or to interfere with polymerization if the reaction solvent is returned directly to the reactor process, it does not provide the opportunity to use the low temperature reaction solvent for other cooling purposes

[0010] However, this solution polymerization reactor is only suitable for operation under lower viscosity conditions, thus limiting the single-pass conversion rate of isobutylene monomer and the increase of glue concentration. The conversion rate is only 20-30%, and the monomer concentration is only 10%. %, so the energy and raw materials consumed per unit product are very high, and the production efficiency of the device is low, which makes it difficult to promote and develop this method so far

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