Polymerization manufacturing technique and device for polyamide

Abstract

The invention relates to a polymerization manufacturing technique and device for polyamide. The manufacturing technique comprises the steps of feeding molten caprolactam, titanium dioxide, benzoic acid and an additive, dynamically mixing at a high temperature for prepolymerization and postpolymerization, granulating, pre-extracting, extracting and drying to obtain the final product. The device comprises a melting system, a feed system, a high-temperature dynamic mixing system, prepolymerization and postpolymerization towers, a pre-extraction column, an extraction column, a recycling system and a drying tower. According to the invention, a high-temperature dynamic mixing tank is set additionally. The mixing of the raw materials and hydrolysis for ring opening and dehydration of polyamide are performed at a state of dynamically mixing to achieve a more sufficient and stable pre-addition polymerization and a more uniform and stable molecular distribution of post-polycondensation. A slice and a water separator of the extraction column are used for mainly extracting oligomers through the pre-extraction column and extracting a caprolactam monomer through the extraction column with a stable concentration. A slice cooler of the drying tower is used for cooling the slices rapidly. An extraction water recycling system is used for recycling the oligomers in the pre-extraction water and the caprolactam monomer in the extraction water.

Description

technical field [0001] The invention relates to a process and equipment for polyamide polymerization production. Background technique [0002] At present, my country's polyamide nylon 6 slice polymerization process mainly refers to foreign imported equipment and foreign advanced technology, which mainly include Gemma, Inventa-Kafischer, Agafel, Noy and so on. However, the imported equipment and technology cannot be used for high-end civilian high-speed spinning chips, especially for high-end fine-denier spinning chips. The problem will be more obvious. The produced chips can only be used to produce conventional chips and low-end engineering plastic chips. , As a result, domestic slices for high-end civilian use mainly rely on imports. The imported equipment consists of caprolactam melter, titanium dioxide compounder, benzoic acid compounder, caprolactam feed tank, pre-polymerization tower, post-polymerization tower, granulator, extraction tower, drying tower and conveying a...

AI Technical Summary

Problems solved by technology

[0004] 1. The molecular weight distribution of the polymerization reaction is too wide, and the molecular weight changes greatly;

[0005] 2. The extraction system has the problem that the slices are oxidized and there is no way to extract oligomers;

[0006] 3. The drying temperature is too high, and the slice drying adopts high temperature drying to greatly increase the solid phase viscosity of the slice

[0012] Although this patent solves the problem of solid-phase thickening, it also improves the internal quality and quality of slices, but it has not solved the problem of oligomer extraction in slices and the recovery of caprolactam monomer in extraction water.

Images