Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization

A technology of aminocaproic acid hydrochloride and aminocaproic acid, which is applied in chemical instruments and methods, preparation of organic compounds, drug combination, etc., can solve the problems of cumbersome preparation procedures, low product yield, high production cost, etc., and achieve improvement The effect of high purity, high conversion rate, and less by-products

Inactive Publication Date: 2010-10-13
NINGBO UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The technical problem to be solved in the present invention is: for the recovery and reuse of nylon-6 waste, and the existing preparation procedures for the preparation of 6-aminocaproic acid are relatively cumbersome, the production cost is high, the product yield is low, and the by-products For many and difficult separation problems, a method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by depolymerizing nylon-6 waste is provided. The process is simple and does not use cation exchange resin for separation, saving Production time, improve production efficiency; preparation conditions are mild, no complicated chemical reaction steps and harsh test conditions are required, production costs are reduced, and the prepared 6-aminocaproic acid has high purity and high yield

Method used

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  • Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization
  • Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization
  • Method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization

Examples

Experimental program
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Effect test

Embodiment 1

[0026] (1) Add 30% industrial by-product hydrochloric acid of 1000Kg in the enamel reaction still with condensing reflux device and hydrochloric acid absorbing device at the top, add 750Kg water again, add 1000Kg waste material nylon-6 while heating, under normal pressure and 100 React at -110°C for 10 hours to obtain an acidolysis solution;

[0027] (2) Vacuumize the reactor until the absolute pressure is less than 10KPa and maintain it for 30 minutes, cool the acid solution to 35°C, filter to remove the residue, then add 80Kg of activated carbon for decolorization to obtain crude 6-aminocaproic acid hydrochloride solution ;

[0028] (3) The obtained thick 6-aminocaproic acid hydrochloride solution is evaporated under reduced pressure to 30-40% of the total volume, cooled to 30-45° C., and the precipitated thick 6-aminocaproic hydrochloride is filtered and used 2 times the volume of industrial ethanol was recrystallized and dried to obtain refined 6-aminocaproic acid hydroch...

Embodiment 2

[0031] Step (1) (2) is the same as embodiment 1.

[0032] (3) Add commercially available concentrated ammonia water to the thick 6-aminocaproic acid hydrochloride solution obtained in step (2) to neutralize the solution to about pH=7, evaporate and concentrate under reduced pressure to the total volume of the solution after neutralization 20%, add industrial ethanol with 4 times the remaining volume while hot, and after fully stirring, naturally cool to room temperature, filter the precipitated 6-aminocaproic acid, wash and dry with absolute ethanol to obtain refined 6-aminocaproic acid white powder, yield Greater than 90%, purity 98%.

[0033](4) The ethanol filtrate in the step (3) is combined with the ethanol used in the washing step, rectified in a rectification tower, and the cuts at 75-80° C. are collected to obtain a 95% aqueous ethanol solution for recycling. Continue to distill part of the water until the residual liquid in the tower kettle begins to crystallize and ...

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Abstract

The invention discloses a method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by using nylon-6 waste through depolymerization. The method is characterized by comprising the following steps of: depolymerizing the nylon-6 waste at the temperature of between 100 and 110 DEG C under constant pressure by using 10 to 20 percent solution of hydrochloric acid so as to obtain acidolysis solution, and filtering, separating, purifying, and drying to obtain refined 6-aminocaproic acid hydrochloride; and introducing ammonia into the solution of 6-aminocaproic acid hydrochloride to neutralize the solution to the pH of between 3 and 9, adding industrial alcohol in a volume 3 to 5 times that of the solution, and recrystallizing to obtain the refined 6-aminocaproic acid. The method has the advantages of simple technical process, low production cost, a few by-products, high yield of the aminocaproic acid, and safe production process.

Description

technical field [0001] The invention relates to a method for producing 6-aminocaproic acid hydrochloride and 6-aminocaproic acid by depolymerizing nylon-6 waste with acid suitable for industrial production. Background technique [0002] 6-Aminocaproic acid, referred to as 6-ACA, is generally produced by direct chemical synthesis, caprolactam or caprolactam polymer (nylon-6 frit, waste silk, waste fabric, fishing nets, etc.) after hydrolysis and refining. 6-Aminocaproic acid (6-ACA) is used for the synthesis of caprolactam and the subsequent production of nylon-6. 6-ACA can also be directly used as a raw material for the production of nylon-6. In addition, 6-aminocaproic acid is widely used as a hemostatic agent in the medical field, and has obvious effects on some severe bleeding caused by increased hemolytic activity of cellulose protein. It is suitable for acute diseases such as oozing or local bleeding during various surgical operations, obstetrics and gynecology bleedin...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C229/08C07C227/18A61P7/04
Inventor 王邃孙利民郭智勇李海龙张振民
Owner NINGBO UNIV
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