| 摘要 |
<p>Prodn. of (mixts.) contg. crystalline (mono -trichloro)-tetra(monopotassium dichloro pentaisocyanurate (I) comprises reacting an opt. amino-substd. triazine (II) with >=a stoichiometric amt. of KOCl in an aq. medium of pH 3.2-5.7 at 35-70 degrees C., esp. 45-65 degrees C. for 5 min. All available sites on (II) ore N-chlorinated and any exocyclic N,N-dichloro nitrogens removed. The mixt. is then cooled to ppte. (I), esp. to 20 degrees C. (II) is poure or crude cyanuric acid; ammeline; ammelide (opt. complexed with ammeline); and/or cyanuric acid:melamine complex. Pref. the soln. contains 3-20, esp. 6-14 wt.% (II). By maintaining a pH of 3.5-4.0 a mixt. of (I) and crystalline (monotrichloro) monopotassium dichloro) diisocyanurate (III) is ppted., while at pH 4-5.5, esp. 4.7-5.0, (I) alone is obtd. There is no need to purify crude cyanuric acid by acid hydrolysis and separate sources of pure K dichloroisocyanurate and trichloroisocyanuric acid are not required. Excellent yields and prod. purity are achieved.</p> |
