Process for the isolation and recovery of polymers

Claim 2

In a process for the recovery of polymers from their solutions the steps comprising: a. feeding steam under a pressure of at least about 150 psig into a high shear mixing zone of the central section of a cylindrical casing; b. feeding a film of the polymer solution into the high shear mixing zone, the hydrocarbon solvent to said solution having a maximum boiling point below the temperature of the steam; c. contacting the steam and solution in the high shear zone whereby at least 95% of the solvent is vaporized, and solid polymer particles are formed; d. passing the mixture of particles in substantially dry powdered or slightly agglomerated form, vaporized solvent, and steam to a cyclone separator, whereby solvent vapors and steam are separated from said polymer powder particles, said particles bearing condensed steam and residual solvent in minor amounts; e. substantially freeing the particles from solvent with sweep steam f. and substantially freeing the particles from condensed steam with hot air.

Claim 3

A process according to claim 1 wherein the mixture of polymer, solvent and steam exits from the high shear zone under at least sonic conditions.

Claim 4

A process according to claim 2 wherein the polymer being recovered is selected from the group consisting of block copolymers of monoalkenyl arenes with conjugated dienes and hydrogenated derivatives of the same.

Claim 5

A process according to claim 1 wherein superheated steam is utilized in step a.

Claim 6

A process according to claim 1 wherein the steam: polymer solution weight ratio in step c immediately prior to contact is between about 0.5 and 3.0.

Claim 7

A process for the recovery of polymers from their solutions according to claim 1 which comprises: a. feeding steam superheated 100 to 500*F above saturation temperature at 150 to 700 psig into a high shear mixing zone; b. feeding a film of a hydrocarbon solution of a polymer into said zone, said polymer being selected from the group consisting of block copolymers of monoalkenyl arenes with conjugated dienes and hydrogenation products thereof; c. contacting the steam and solution in the high shear zone whereby at least about 98% of the hydrocarbon solvent is vaporized at least when the mixture exits from the zone under at least sonic conditions, said mixture upon exit comprising substantially dried polymer powder or slightly agglomerated particles bearing superficial amounts of residual solvent and condensed steam together with steam and vaporized solvent; d. passing the mixture tangentially into a cyclone separator whereby the particles are separated from the gaseous components of the mixture; e. substantially freeing the particles from residual solvent by contact with sweep steam; f. and substantially freeing the particles from condensed steam by drying with hot air.

Claim 8

In a process for the recovery of polymers from their solutions the steps comprising: a. feeding steam under a pressure of at least about 150 psig into a high shear mixing zone of the central section of a cylindrical casing; b. feeding a film of the polymer solution into the high shear mixing zone, the hydrocarbon solvent of said solution having a maximum boiling point below the temperature of the steam; c. contacting the steam and solution in the high shear zone whereby at least 95% of the solvent is vaporized, and solid polymer particles are formed; d. passing the mixture of particles in substantially dry powdered or slightly agglomerated form, vaporized solvent, and steam to a cyclone separator, whereby solvent vapors and steam are separated from said polymer powder particles, said particles bearing condensed steam and residual solvent in minor amounts; e. passing the mixture of resulting particles from step d thru a devolitilizing extruder which devolatilizes, dries, extrudes and pelletizes the product.

Claim 9

In a process for the recovery of polymers from their solutions the steps comprising: a. feeding steam under a pressure of at least about 150 psig into a high shear mixing zone of the central section of a cylindrical casing; b. feeding a film of the polymer solution into the high shear mixing zone, the hydrocarbon solvent of said solution having a maximum boiling point below the temperature of the steam; c. contacting the steam and solution in the high shear zone whereby at least 95% of the solvent is vaporized, and solid polymer particles are formed; d. passing the mixture of particles in substantially dry powdered or slightly agglomerated form, vaporized solvent, and steam to a cyclone separator, whereby solvent vapors and steam are separated from said polymer powder particles, said particles bearing condensed steam and residual solvent in minor amounts; e. passing the mixture of resulting particles from step d thru a devolitilizing extruder which devolatilizes, dries, extrudes and pelletizes the product.