High solids content emulsion polymerisation without intermediate seeds. Part II. In situ generation of bimodal latices

A process for the production of high solid content latexes with low viscosity that does not require the use of intermediate seeds is developed. It is shown that the second population of a bimodal latex can be generated by controlled homogeneous nucleation through the use of a combination of an initiator that generates charged free radicals and a mixed surfactant system that is very rich in non-ionic surfactant. The process was shown to be reproducible, and was used to produce a latex with a solid content of almost 77% (v/v) and a viscosity of 1.5 Pa s at a shear rate of 20 s−1.