Method for preparing quaternary ammonium salt

Abstract

This invention relates to a method for preparing quaternary ammonium salt. The method comprises: reacting C12-C18 alkyl dimethyl tertiary amine and alkylation reagent at 50-105 deg.C in water to obtain the product. The alkylation reagent is C1-C8 halogenated hydrocarbon. The method has the same effect as conventional method performed in low-carbon alcohol, and has such advantages as low cost and reduced environmental pollution of the solvent.

Description

(1) Technical field [0001] The invention relates to a preparation method of quaternary ammonium salt. (2) Background technology [0002] Quaternary ammonium salt-type cationic surfactants have many excellent properties, and can be used as antistatic agents, softeners, dye retarders, color fixing agents, etc. for fibers, and can also be used as bactericidal disinfectants and hair conditioners for hair cosmetics, etc. in various industries. The quaternary ammonium salt type cationic surfactant has strong alkalinity, does not produce free amine in alkaline solution, and has stable properties. [0003] From a structural point of view, quaternary ammonium salts are formed by replacing four hydrogen atoms on ammonium salts with organic groups, and are usually prepared by reacting tertiary amines with alkylating agents. The alkylating reagents include: alkyl halides such as methyl chloride and benzyl chloride, dialkyl sulfates such as dimethyl sulfate, epoxides such as ethylene o...

AI Technical Summary

Problems solved by technology

Its existing main defect is: 1) use the polar media such as ethanol, isopropanol as reaction cosolvent cost height

2) Using polar media such as ethanol and isopropanol as a reaction co-solvent causes waste of resources

3) Polar media such as ethanol and isopropanol are used as reaction co-solvents, which will cause environmental pollution after volatilization of ethanol and isopropanol

The above-mentioned publications only relate to the preparation of tertiary ammonium salts by unsaturated tertiary amines, but do not involve the preparation of quaternary ammonium salts in water by alkyl tertiary amines, and there is no further research on alkyl tertiary amines, alkylating reagents and reaction parameters.