| 摘要 |
<p>The invention concerns a method for making aqueous solutions of unsaturated quaternary ammonium salts of formula (I) by reacting, in the presence of water, N,N-dimethylaminoethyl acrylate with a quaternizing agent of formula (II): R-Cl. Said method is characterised in that it consists in: (a) in a closed reactor containing all the N,N-dimethylaminoethyl acrylate and which has been pressurised with air or depleted air at 0.5 to 3 bars, carrying out the reaction by continuously introducing, at temperature ranging between 35 to 65 °C, the quaternizing agent (II), and water, until the desired concentration of salt (I) in water is reached, the water being introduced only when 0-20 wt. % of the amount required for the quaternizing agent (II) reaction has been added, and the pressure at the end of the reaction capable of reaching 9 bars; then depressurising the reactor while maintaining the oxygen content constant by simultaneous introduction of air, and after returning to atmospheric pressure, eliminating the residual quaternizing agent. (I) and (II). R = methyl or benzyl.</p> |
