Material mixer used for high temperature difference quick reaction

Abstract

The invention discloses a material mixer for fast reaction of high temperature difference, which leads mixing reaction to go on smoothly, and the invention is applied in the production of aramid fiber, the continuous and stable industrial production of poly-para-phenylene two formyl to phenylene-diamine resin is achieved. The mixer comprises a casing body, a mixing bin n the casing body, two fluid channels which lead to the mixing bin and a feed inlet, the upper end of the mixing bin is a piston bin, both lateral walls of a piston are provided with vertical guiding grooves, the upper portion of the feed inlet is provided with a bolt which penetrates the guiding grooves on both sides of the piston. Two monomers which are reacted can get into a polymerization reactor after continuously and stably mixing with accurate stoichiometry coefficient to be proportioning in dissolvent and cosolvent by adopting the invention, resin with high molecular weight can be continuously and stably produced.

Description

technical field [0001] The invention relates to a material mixer for rapid reaction with high temperature difference, which is especially suitable for using NMP-CaCl 2 Mixer for initial mixing reaction for continuous production of poly(p-phenylene terephthalamide) resin for solvent. Background technique [0002] In 1935, DuPont scientist Carothers invented aliphatic polyamide fiber (ie, polyhexamethylene adipamide <nylon 66> fiber), which opened up a new world for the application of polyamide fiber to the industrial field. Among them, DuPont 1966 Published in 2010 a remarkable high-performance poly-p-phenylene terephthalamide fiber, its official trade name is Kevlar(R) (referred to as para-aramid in my country, aramid 1414 and aramid II). Because of its high strength, high modulus and high temperature resistance, it is widely used in tire cords, high-strength rigging, high-pressure container shells, automobile friction sheets, building geotechnical materials, various r...

AI Technical Summary

Problems solved by technology

At present, because poly-p-phenylene terephthalamide resin uses NMP-CaCl 2 For solvents, but studies have found that terephthaloyl chloride and NMP-CaCl 2 The solvent can react at a certain temperature. Although such a small amount of reaction will lead to a low molecular weight of the final resin, it can only be that p-phenylenediamine is dissolved in NMP-CaCl 2 Exist in liquid form in the system, and terephthaloyl chloride exists in molten form; The second is that the reaction speed of the two monomers is particularly fast and a phase change occurs during the reaction (that is, it changes from liquid to gel state quickly, and then reacts It becomes solid after a period of time), so the two monomers are required to be mixed evenly in a short period of time and removed in time, otherwise the polymer will exist in the form of gel and it is difficult to flow if the residence time is too long, and the material is still in the mixer Although the residence time is short, there may still be a small amount of polymer in the resin in the form of small gel, which is easy to stick to the wall of the mixer. To make the reaction continue and stably, it is necessary to remove the glue sticking to the wall of the mixer in time. The material is scraped away and sent to the reactor for further reaction; third, in order to obtain high molecular weight resin and control the speed of the initial mixing reaction, the initial mixing reaction of the two monomers is required to be carried out at low temperature, so not only NMP-CaCl 2 The prepolymer system such as p-phenylenediamine enters the mixer at a very low temperature, and it is best to maintain a low temperature in the mixer, but terephthaloyl chloride is in a molten state and the flow rate is much smaller than that of the prepolymer system. way into the mixer, so the feed port of terephthaloyl chloride may be affected by the low-temperature system in the mixer and cause terephthaloyl chloride to solidify and be blocked, so that continuous mixing cannot be carried out smoothly

[0007] In short, due to the problem of the mixer, the production of poly-p-phenylene terephthalamide resin cannot be continuously and stably industrialized, but because poly-p-phenylene terephthalamide fiber is widely used, the potential demand in my country is very large. Large, and the para-aramid fibers used in my country are all imported, and the import price has also skyrocketed in recent years (15 times in 8 years)

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