High styrene content stable polymer polyols using epoxy resin-modified polyols as dispersants

摘要

Very low viscosity polymer polyols having high styrene/acrylonitrile ratios and good stability are obtained by a process comprising polymerising, via a free-radical reaction, a monomer component, in the presence of a polyol mixture comprising a major portion of a base polyol unmodified with epoxy resin and a minor portion of an epoxy resin-modified polyol as a dispersant. The epoxy resin-­modified polyols useful as dispersants may be made by reacting a polyol initiator having an active hydrogen functionality of 3 to 8 and one or more alkylene oxides with an epoxy resin. It is preferred that all of the epoxy resin-modified base polyol dispersant be initially charged to the reactor, along with part of the base polyol.