Method for high temperature phase separation of solutions containing polymers

Claim 1

A process for the recovery of hydrocarbon polymer from a solution of said polymer comprising: (i) preparing the solution of polymer in a reactor; (ii) adding to the thus-prepared solution of polymer an effective amount of at least one low molecular weight hydrocarbon selected from the group consisting of unsubstituted and halogenated C 1 alkanes and halogenated C 2 -C 4 alkanes, alkenes, alkynes with the proviso that said hydrocarbon is a gas at ambient temperature and pressure; provided, however, that where the low molecular weight hydrocarbon is a C 1 halogenated or unhalogenated alkane, it is utilized at about 2 to about 10.8 wt. % based on the polymer solution, and further provided that where the low molecular weight hydrocarbon is a C 2 halogenated or unhalogenated alkane, alkene, or alkyne, it is utilized at about 2 to about 21 wt. % based on the polymer solution; still further provided that where the low molecular weight hydrocarbon is a C 3 -C 4 halogenated or unhalogenated hydrocarbon it is utilized at about 2 to about 30 wt. % based on the polymer solution; (iii) subjecting said solution including said hydrocarbon to a temperature at which two liquid phases can form and a pressure sufficient to prevent the creation of a vapor phase; (iv) adjusting said pressure such that a polymer-rich liquid phase and a polymer-lean liquid phase are formed; (v) separating said polymer-rich liquid phase from said polymer-lean liquid phase; and (vi) recovering said polymer from said polymer-rich liquid phase.