| 摘要 |
A method is disclosed for the preparation of flowable aqueous solutions of betaines of the general formula <IMAGE> wherein R1 is the alkyl portion of a fatty acid with 6 to 18 carbon atoms, R2, R3 are the same or different and represent alkyl groups with 1 to 4 carbon atoms x is 2 or 3 and y is 1, 2 or 3 by quaternization of the fatty acid amide R1CONH(CH2)xNR2R3 with omega -halogenalkylcarboxylic acids X(CH2)COOY or their salts (X=halogen, Y=a hydrogen, alkali or ammonium ion) in aqueous solution at elevated temperatures. The preferably still hot solution, obtained pursuant to the invention after the reaction, is brought to the desired concentration, if necessary, by the evaporation of water. Before or after the concentration of the solution is adjusted to the desired value, mineral acid is added in such amounts, that the pH of the solution becomes 1 to 4.5. If hydrogenated coconut fatty acids are used as the fatty acid mixture for the preparation of the betaine, it is possible to prepare flowable solutions with a solids content of about 54% by weight. Water-soluble nonionic surfactants may be added to the betaine solution.
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