Reaktion #50905

Reaktionsgleichung

sodium hydroxide

benzotriazole

sodium hydroxide

silver nitrate

→

Silver Benzotriazole Salt

Lösungsmittel

water

water

Solution C

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA stirred reaction vessel
2. 2
   workup.ADDITIONwas added to the kettle at the accelerated flow rate
3. 3
   SonstigeThis process was terminated when Solution C
4. 4
   Sonstigeat 40° C.
5. 5
   workup.ADDITIONwas added to the kettle
6. 6
   WaschenThe coagulum was washed twice with 5 liters of deionized water
7. 7
   workup.ADDITIONre-dispersed

Vorschrift

A stirred reaction vessel was charged with 85 g of lime-processed gelatin, 25 g of phthalated gelatin, and 2000 g of deionized water. A solution containing 185 g of benzotriazole, 1405 g of deionized water, and 680 g of 2.5 molar sodium hydroxide was prepared (Solution B). The mixture in the reaction vessel was adjusted to a pAg of 7.25 and a pH of 8.0 by addition of Solution B, and 2.5 molar sodium hydroxide solution as needed, and maintaining it at temperature of 36° C. A solution containing 228.5 g of silver nitrate and 1222 g of deionized water (Solution C) was added to the kettle at the accelerated flow rate defined by: Flow=16(1+0.002t2) ml/min (where t is the time in minutes), and the pAg was maintained at 7.25 by a simultaneous addition of Solution B. This process was terminated when Solution C was exhausted, at which point a solution of 80 g of phthalated gelatin and 700 g of deionized water at 40° C. was added to the kettle. The mixture was then stirred and the pH was adjusted to 2.5 with 2 molar sulfuric acid to coagulate the silver salt emulsion. The coagulum was washed twice with 5 liters of deionized water, and re-dispersed by adjusting pH to 6.0 and pAg to 7.0 with 2.5 molar sodium hydroxide solution and Solution B. The resulting silver salt dispersion contained fine particles of silver benzotriazole salt.

Quelle