Condensed resin dispersion and process for its production

A condensed resin dispersion having fine particles of a particle size ranging from 0.01 to 5 .mu.m of a condensed resin dispersion stably in a polyether polyol (c), said condensed resin being the reaction product of an aldehyde and a compound condensable with the aldehyde, or a precondensate of these reactants, wherein the fine particles of the condensed resin are fine condensed resin particles formed by said reaction and precipitation conducted in an isocyanate-modified liquid polyether (b) which is (i) an isocyanate-modified polyether obtained by reacting, with a mixture of a polyether (a) and a low molecular weight polyamine, less than the equivalent amount of an organic polyisocyanate or a partially blocked organic polyisocyanate, (ii) an isocyanate-modified polyether obtained by reacting, with a mixture of a polyether (a) and a low molecular weight polyamine and a blocking agent, less than the equivalent amount, based on the total equivalent amount thereof, of an organic polyisocyanate, or (iii) an isocyanate-modified polyether obtained by reacting, with a mixture of a polyether (a) and a low molecular weight polyamine, more than the equivalent amount of an organic polyisocyanate, followed by reaction of the reactive material with a blocking agent.