CONTINUOUS FREE RADICAL POLYMERIZATION IN A WIPED SURFACE REACTOR

A bulk polymerization process for free radical polymerization of vinyl monomers in a wiped surface reactor is disclosed. Referring to Figure 1; monomer streams (5) (after purification and silica gel column 2) and (7) are combined with free radical initiator (9) to form a premix (16). Pump (18) transfers the premix stream (22) through static mixer (24) into a wiped surface reactor (27). The reactor can be a counter rotating twin screw extruder which produces polymer stream (36) without the need of solvent and using residence times much shorter than prior art solution or emulsion processes.Some unique pressure sensitive adhesive acrylate polymers have been produced. They are believed to have a relatively high degree of branching. The bulk polymerization process permits the manufacture of pressure sensitive adhesive articles by extruding directly from the twin screw extruder onto a substrate.