Rapidly dissolving, water-soluble polymers and spray drying method for their production

摘要

A free-flowing particle mixture of a water-soluble polymer wherein the particles are (1) no smaller than about 325 mesh, (2) at least 50% thereof are larger than about 120 mesh and (3) none are larger than about 20 mesh, said mixture containing no more than about 12% volatiles and said particles comprising hollow, porous structures having at least one opening in their walls, the walls comprising small adhering aggregates of the same compositions and a method for producing such a mixture comprising spraying a water-in-oil emulsion of said polymer, using a specific type and orifice-size nozzle, into a gas stream at an outlet gas temperature of at least about 212 DEG F. and at a dryer residence time of at least about 40 seconds.