Dispersing solid additives in polymers

摘要

A method for dispersing solid forms of additives in polymers involves adding dispersions or solutions of additive(s) to a solution of polymer in a tubular mixer (preferably in the presence of a stationary mixer). The mixer leads to a steam precipitation step wherein all fluid ingredients in the mixture are volatilized leaving the solid additive and resin in the desired ratio. This results in a uniform dispersion of the additives in the polymer matrix. As a result of the high dispersion, physical properties of a thermoplastic resin, to which the polymer matrix has been added are preserved. In one illustration, PTFE as a drip inhibitor additive, is added to polycarbonate to obtain a highly dispersed PTFE concentrate of improved drip-inhibition without loss of mechanical properties when added to a thermoplastic molding resin.