PROCESS FOR OBTAINING AQUEOUS POLYMER DISPERSIONS

摘要

The process comprises the following phases : formation of a pre-emulsion of monomers in water ; transfer into the polymerisation reactor with stirring, of (1) reaction stock consisting of a water solution of a surfactant, in an amount by weight relative to the weight of final polymer dispersion of 1 - 15% ; (2) a portion of the pre-emulsion prepared in the previous phase, in an amount of 1% - 10% by weight of the initial pre-emulsion ; phase C.1 : initiation of the polymerisation ; phase C.2 : polymerisation of the monomer mixture at 30 - 90 DEG C, by gradually adding into the reactor, separately, the initiator solution and the remaining portion of the pre-emulsion with an added salt, which is soluble in water at 25 DEG C to at least 1% by weight, in an amount so as to have a salt concentration in the added pre-emulsion of 0.02 - 0.25% by weight ; phase C.3 : scrubbing of the residual monomers.