Preparation of rhodamine dyes in granule form by direct cooling

摘要

Salts of esterified rhodamine dyes are prepared in granular form by precipitating the rhodamine dyes with sodium chloride from an aqueous medium containing a water-miscible solvent by adding the sodium chloride at 80 DEG -100 DEG C., which precipitates the dyes in liquid form from the aqueous medium, then stirring the liquid dyes to convert them into a droplet form and then chilling the droplets by direct cooling to below 65 DEG C.