Method for preparing isooctyl thioglycolate by adopting tail liquid in the production process of O-alkyl-N-alkyl sulfide expelling carbamate

Abstract

The invention discloses a method for preparing isooctyl thioglycolate by adopting tail liquid in the production process of O-alkyl-N-alkyl sulfide expelling carbamate, comprising the following steps:a. acidifying and purifying tail liquid, removing separated suspending organic matters; b. extracting the acidified liquid by an extracting agent, esterifying to obtain rough ester; c. carrying out reduced pressure distillation on the rough ester and obtaining the isooctyl thioglycolate. The method is characterized in that: in the extraction and esterification processes, isooctane is firstly takenas the extracting agent to extract and esterify the acidified liquid to obtain organic mixture; the organic mixture is taken as an extracting agent to extract and esterify the new acidified liquid; and the obtained organic mixture after extraction and esterification is taken as an extracting agent to extract and esterify the new acidified liquid at least once. The invention has the advantages ofreasonable production process, raw material saving, low production cost and high product quality and is a reasonable method for recycling the tail liquid in the production process of the O-alkyl-N-alkyl sulfide expelling carbamate.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for recycling thioglycolic acid in the tail liquid of O-alkyl-N-alkylthiocarbamate production. Background technique [0002] Isooctyl thioglycolate is a new type of non-toxic plastic additive. It is a heat stabilizer widely used in the processing of PVC and other plastic products. In recent years, with the rapid development of the field of polymer materials, thioglycolate isoct The demand for octyl esters also increases accordingly. The current preparation methods of isooctyl thioglycolate all have problems such as high raw material cost, complex production process, and long production cycle. And the production technology and market have been controlled by foreign developed countries. [0003] O-alkyl-N-alkylthiocarbamate is a kind of thiocarbamate, in the production of thiocarbamate such as O-alkyl-N-alkylthiocarbamate, a large amount of The ratio of waste water (tai...

AI Technical Summary

Problems solved by technology

Utilize this method to produce isooctyl thioglycolate, the content of thioglycolic acid and ester in the crude ester obtained after extraction is low, and must add the thioglycolic acid of high concentration in the organic phase of loading thioglycolic acid before esterification, increased production cost; Moreover, when removing organic substances in the acidification solution, volatile organic solvents such as petroleum ether and ether are used, which has caused repeated pollution to the environment.