| 摘要 |
The invention relates to the process for making a highly stable polyvinylpyrrolidone-halogen complex by forming a reaction solution in a diffusion zone containing a 3 to 9 percent aqueous solution of polyvinylpyrrolidone and halogen dissolved in an alcohol solution wherein the concentration of alcohol is not less than 40% of the total solutions and wherein a portion of the halogen requirement, up to 35%, may be in the form of hydrogen halide or a salt thereof; reacting the polypyrrolidone and halogen components and forming a water/alcohol azeotrope simultaneously with the corresponding polyvinylpyrrolidone-halogen complex; subjecting the reacted mixture to azeotropic distillation to remove an aqueous alcohol distillate; recycling the distillate to the halogen solubilizing or diffusion zone and subjecting the remaining liquid product solution, containing not more than about 35% solids, to spray drying to recover the polyvinylpyrrolidone/halogen product in the form of a particulate solid wherein each particle is of a uniform brownish yellow color throughout. |
