Process for the production of a dispersion of condensation polymer particles containing a modifying agent

Claim 1

A process for the production of a dispersion of condensation polymer particles in a hydrocarbon or chlorinated hydrocarbon liquid medium in which the polymer is insoluble, wherein the disperse particles of polymer are of a size from 0.1μ to 100μ and incorporate at least one modifying agent for the polymer, the process comprising heating in the said liquid medium at polymerisation temperature an appropriate condensation polymer-forming reactant or reactants, the reactant or at least one of the reactants being present as a liquid disperse phase in an emulsion of which the continuous phase is constituted by the said liquid medium and which is produced with the aid of from 1 to 10 percent by weight, based on the disperse phase, of an emulsifying agent which is a polymeric material containing in its molecule at least one chain-like component of a type which is soluble and non-self-associated in the liquid of the disperse phase and at least one chain-like component of another type which is soluble and non-self-associated in the liquid of the continuous phase, the average molecular weight of the individual components being at least 1,000, the total molecular weight of the individual components of each type being at least 3,000 or at least n × 1,000 where n is the number of the individual components of the other type, and the ratio of the total weights of the individual components of the two types being from 3:1 to 1:3, in addition one of the chain-like components of the emulsifying agent which is soluble in a disperse phase being also capable of associating with the polymer produced, dispersing in the said liquid phase of the emulsion prior to completion of the polymer-forming condensation reaction the modifying agent or agents and then completing the polymer-forming reaction.