Process for water soluble polymer recovery

Claim 1

A PROCESS FOR RECOVERING A WATER-SOLUBLE ADDITION POLYMER OF A POLYMERIZABLE COMPOUND CONTAINING A CH2=C<GROUP FROM AN AQUEOUS SOLUTION THEREOF COMPRISING (1) BLENDING SAID AQUEOUS SOLUTION WITH AN ORGANIC PRECIPITATING AGENT, AT A TEMPERATURE BETWEEN ABOUT 0*C. AND A TEMPERATURE JUST BELOW THE BOILING POINT OF SAID PRECIPITATING AGENT, IN AN AMOUNT SUFFICIENT TO REDUCE THE VISCOSITY OF SAID SOLUTION AND TO PRODUCE A PERMANENT UNIFORM CLOUDINESS THROUGHOUT THE MEDIUM, WHICH CLOUDINESS DOES NOT DISSIPATE ON CONTINUOUS AGITATION, BUT NOT IN AN AMOUNT SUFFICIENT TO PRECIPITATE SAID POLYMER THEREFROM, (2) DILUTING THE BLEND THUS PREPARED WITH A FURTHER QUANTITY OF AN ORGANIC PRECIPITATING AGENT IN AN AMOUNT SUFFICIENT TO PRECIPITATE THE POLYMER IN THE FORM OF FINE DISCRETE PARTICLES, (3) SEPARATING THE SOLID PRECIPITATED POLYMER FROM THE RESIDUAL FLUID, AND (4) DRYING THE SEPARATED POLYMER, WHEREIN SAID PRECIPITATING AGENT IS AT LEAST PARTIALLY SOLUBLE IN WATER, INERT TO SAID POLYMER AND IN WHICH SAID POLYMER IS SUBSTANTIALLY INSOLUBLE AND WHEREIN SAID AQUEOUS SOLUTION OF SAID PRECIPITATING AGENT IS A NON-SOLVENT FOR SAID POLYMER AT A CONCENTRATION UP TO AND INCLUDING SATURATION.