Novel three kettle polymerization process of chinlon 6

Abstract

The invention discloses a novel process of continuously polymerizing and producing chinlon 6 slices. The process comprises the following steps: directly a pure caprolactam raw material with a reclaimed material through concentration by conventional triple effect evaporation; carrying out reactions in a pre-reaction kettle, a pre-polymerization kettle and a post-polymerization kettle; and carrying out subsequent conventional treatment processes to produce the high quality chinlon 6 slices. Compared with the conventional methods, the low concentration reclaimed material is efficiently utilized, and the needed high concentration slurry treated by the concentration kettle can be used for continuous and stable production. The proportion adjustment range of the reclaimed material permitted in the used raw materials is great, and the water content range of the material permitted is great. The whole technical process is simple to operate and simple in equipment structure. The three reaction kettles have different technical control parameters, so that the conversion ratio of materials is effectively improved. The relative viscosity of the obtained chinlon 6 product can reach 2.4-3.6, and the strength and the tensile property of the chinlon 6 product can be widely applied to production of downstream products.

Description

technical field [0001] The invention relates to a new process for continuous polymerization production of nylon 6 slices, which are raw materials for chemical fiber spinning. Background technique [0002] At present, the production of raw materials for spinning grade nylon 6 chips is a polymerization process using water as a ring-opening agent, commonly known as a hydrolysis polymerization process. In industrial production, the hydrolytic polymerization process is currently classified into one-stage polymerization process and two-stage polymerization process due to the different number of polymerization tanks. [0003] One-stage polymerization, also called single-pot polymerization, is represented by Swiss Uhde Inventa-Fischer Company and Italian NOY Company. This process is characterized by simple control and easy operation. Difficult, and the material stays in the polymerization tank for a long time (more than 24 hours). [0004] Two-stage polymerization, that is, two-po...

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Problems solved by technology

[0003] One-stage polymerization, also called single-pot polymerization, is represented by Swiss Uhde Inventa-Fischer Company and Italian NOY Company. This process is characterized by simple control and easy operation. Difficult, and the material stays in the polymerization tank for a long time (more than 24 hours)

[0004] Two-stage polymerization, that is, two-pot polymerization, represented by Lurgi Zimmer Company, PE Company and Aquafil Company in Germany. The characteristic of this process is that the control is slightly more complicated than that of the one-stage method, but the internal structure of the polymerization kettle equipment is simple, and the equipment is easy to process. The residence time of the material in the polymerization tank is relatively short (about 12 hours)

The whole process is complicated, the energy consumption is high, and there is still a certain amount of waste residue discharge

[0007] Both of the above two polymerization processes do not consider the technology of directly using a high proportion of recycled materials containing a certain amount of oligomers as raw materials for repolymerization

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