| 摘要 |
This invention relates to a process for the preparation of a stabilized aqueous alkali metal-2-hydroxy-4,6-dichloro-s-triazine (AHDT) solution, which entails starting at 5 to 40° C. with a solution containing either the corresponding alkali hydrogencarbonate, acetone, or a mixture thereof, and then, while cooling, adding cyanuric chloride and an alkali lye simultaneously in such a manner that the reaction temperature does not exceed 25° C. and the pH does not drop below 5.5, and during a subsequent stirring time of 2 to 30 hours adding either a very small quantity of alkali lauryl sulfate if the original starting solution contained hydrogencarbonate, or adding alkali hydrogencarbonate if exclusively acetone was used in the first reaction step, and then finally adding an alkali borate and/or a dialkali hydrogenphosphate and/or potassium hexacyanoferrate (II) as buffer. The pH, which should be >=7.0 during the entire process, may, if necessary, be adjusted with an acid to a value between 8.0 and 9.5. The invention also provides for the same alkali metal to be used in all steps of the process. In particular as a result of the alkali hydrogencarbonate co-stabilizer, one obtains with this relatively simple process, after very short reaction times, AHDT solutions which remain stable for a long time and which do not release CO2 at any time during their synthesis, storage or use.
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