Preparation method and application of N-acyl acidic amino acid or salt thereof

Abstract

The invention discloses a preparation method of N-acyl acidic amino acid or a salt thereof. According to the preparation method, fatty acyl chloride and an amino acid are subjected to an amidation reaction under an alkaline condition. The preparation method is characterized in that in the amidation reaction, water is used as a solvent, an acidic amino acid or a salt thereof is used as a main raw material and a small amount of a neutral amino acid or a salt thereof is used as an auxiliary raw material. The preparation method comprises the following steps: under a stirring condition, dropping the fatty acyl chloride into the aqueous solution of the acidic amino acid or the salt thereof; adding an alkali to adjust the pH value of the reaction solution; after a certain amount of fatty acyl chloride is dropped, adding the aqueous solution of the neutral amino acid or the salt thereof, continue to drop the fatty acyl chloride until the dropping is finished and stirring to maintain the reaction. According to the preparation method, the mixed amino acid and the fatty acyl chloride react under a water-phase system, so that the conversion rates of the mixed amino acid and the fatty acyl chloride can be remarkably increased and the amount of residual amino acids is greatly reduced. The product can be directly used as a surfactant after being treated simply, and thus the cost is greatly reduced.

Description

technical field [0001] The invention relates to a surfactant N-acyl amino acid or a salt thereof, in particular to a preparation method of an N-acyl acidic amino acid or a salt thereof, which is a low-cost preparation method of a fatty acyl acid amino acid surfactant; And the application of the N-acyl acidic amino acid prepared by the method. Background technique [0002] N-acyl amino acid or its salt is a kind of compound obtained by acylation of amino acid, usually formed by condensation of fatty acid chloride and amino acid. This type of compound has good surface activity, foaming performance, cleaning performance and mildness, and is widely used in Cosmetics, personal cleaning and care products, and also have broad applications in other fields such as food additives, metal processing, ore flotation, oil extraction, and agriculture, biological products and drug preparation. [0003] N-acyl acidic amino acid or its salt is a kind of compound obtained by amidation of acidi...

AI Technical Summary

Problems solved by technology

Since the acidic amino acid uses water as a solvent in the condensation with acid chloride, its conversion rate is relatively low, usually only 70%, the product quality is low, and the post-treatment is complicated. In actual production, polar organic solvents are mostly used, which can greatly increase the conversion rate to 85-90%, but the problem is that the post-processing is complicated and the cost rises sharply, resulting in high product prices and cannot be used on a large scale like neutral amino acid surfactants

[0004] U.S. Patent US6008390 discloses that in the aqueous phase reaction system, the conversion rate of glutamic acid can be increased to about 85% under the working conditions of a high-energy agitator, but the energy consumption of this process will increase significantly, and it is very difficult to scale up large-scale industrial production equipment At the same time, high-speed stirring leads to too much foam, which reduces the reaction mixing effect, which undoubtedly brings difficulties to production and greatly increases production costs, affecting its market application.

Moreover, in the above-mentioned preparation process, glutamic acid is too much in excess, the cost is high, and the residual amino acid brings trouble to the use in the product.