| 摘要 |
The invention relates to a method for producing a setting retarder for hydrate-forming binders, wherein a) a first reactant A, comprising an amino acid and/or an amino acid derivative, is reacted with b) a second reactant C, comprising an amine-free carboxylic acid and/or an amine-free carboxylic acid derivative, to form a reaction product, characterized in that the reaction occurs at a pH value of 7.5 - 11.5 and the pH value is held constant in the specified range of 7.5 - 11.5 during the reaction. In order to hold the pH value constant in the specified range and to avoid fluctuations, in a method step an aqueous solution of reactant A is presented and a pH of 7.5 - 11.5, preferably 8 - 11, in particular 8.5 - 10.5, is set by adding base. In a second method step, partial amounts of the base and partial amounts of reactant C are alternately added in order to stabilize the pH value during the reaction. |
