Patent ID: 8741986

Claim:
A method for producing an emulsion of plasticized poly(vinyl butyral) in water comprising: feeding into a screw extruder a thermoplastic polymer resin, a plasticizer, a surfactant, and water, wherein said thermoplastic polymer resin is a poly(vinyl butyral) resin having a weight average molecular weight of at least 40,000 Daltons; mixing said polymer resin, said surfactant, said plasticizer, and said water in a first zone within said screw extruder to form a weld; moving said weld to a second zone within said screw extruder; adding water to said weld in said second zone and mixing, thereby causing an inversion in said weld which results in the formation of said emulsion of plasticized poly(vinyl butyral) in water; wherein said polymer resin, said surfactant, said plasticizer, and said water are moved into and through the first zone, to mix the components and form said weld, in less than about 45 seconds; wherein said first zone is set at a pressure of 2×10 6 Pascal to 4×10 6 Pascal and a temperature below 100° C.; and wherein said second zone is set at a pressure of 2×10 6 Pascal to 4×10 6 Pascal and a temperature below 100° C.