| 摘要 |
The present invention relates to a process for the manufacture of aqueous solutions of unsaturated quaternary ammonium salts. The salts can correspond to the following formula (I):in which R represents a methyl or benzyl radical, by reaction, in the presence of water, of N,N-dimethyl-amninoethyl acrylate (DAMEA) with a quaternizing agent of formula (II):in which R is as defined above. Generally, the reaction is carried out in a closed reactor, which includes all the DAMEA and has been pressurized by air or depleted air to 0.5 to 3 bar, by continuously introducing, at a temperature of 35 to 65° C., the quatenlizing agent (II) and the water, until a concentration of salt (I) in the water is obtained. The water starts to be introduced beginning when 0-20% of the amount by weight of the quaternizing agent (II) necessary for the reaction has been added and it being possible for the pressure at the end of the reaction to reach 9 bar. Next, the reactor can be depressurized while keeping the oxygen content constant by simultaneous introduction of air and, after returning to atmospheric pressure, the residual quaternizing agent may be removed. |
