公开(公告)号：GB871776A

公开(公告)日：1961-06-28

申请号：GB4253759

申请日：1959-12-15

Applicant: BASF AG

Inventor： MARKEL KARL ,  WERNER HEINZ-ULRICH ,  PALM ALBERT

Abstract: Chlorinated isocyanuric acid is produced by leading Cl2 into an aqueous solution of sodium or potassium cyanurate until the pH is less than 7, adding an alkali compound, i.e. sodium or potassium hydroxide, carbonate, or bicarbonate, preferably in aqueous solution, in amount equivalent at most to 30% of the free and combined cyanuric acid, and continuing addition of Cl2 until the pH is 5 to 2.5.5-20% solutions of di- Na or K cyanurate or tri- Na or K cyanurate produce pure di- or tri-chloroisocyanuric acid respectively. A mixture of di- and tri-chloroisocyanuric acids may also be prepared. The reaction may be effected at normal or elevated pressure at temperatures below 100 DEG C., preferably below 50 DEG C. for di-chloro-acid and below 40 DEG C. for tri-chloro-acid, particularly -10 DEG to 35 DEG C. The reaction may be in the presence of water-miscible liquids, e.g. methanol, ethanol, acetone, acrylonitrile, aliphatic or aromatic amines, phenols, urea, or formaldehyde. Addition of the alkali compound may be all at once, periodically, or continuously, and the further addition of Cl2 may be during and/or after the alkali compound. The solid crystalline chlorinated isocyanuric acid may be separated from the reaction mixture mechanically, and washed with water, and the mother liquor and washings may be reused in the process. The acid may be dried below 100 DEG C. preferably at below 50 mm. Hg. pressure. Alternatively, the acid may be dried by treating with water-immiscible organic liquids, e.g. benzene or carbon tetrachloride, preferably at below 50 DEG C. in vacuo. Decomposition of the acids or their salts may be inhibited by adding formaldehyde, or salts of phosphorus acid or of hydroxylamines.