Process for preparing normally crystalline vinylidene halide polymers having superior flow properties employing a combination of colloidal silica and non-ionic water soluble cellulose ether having a viscosity of about 5 cp or less as stabilizing agents

Claim 1

In a process of making solid bodies of normally crystalline vinylidene halide polymers in the form of spheroidal globules comprising the steps of forming a mixture of a polymerizable liquid and an aqueous non-solvent liquid medium, the non-solvent liquid medium containing a water-dispersible, water-insoluble, colloidal solid particle emulsifier; mechanically agitating the mixture to disperse the polymerizable liquid as smaller-than-stable droplets in the non-solvent liquid medium; bringing the resulting unstable dispersion to a condition of quiescence, whereby the unstable droplets undergo a limited coalescence to form a stable suspension of droplets; treating the stable suspension with a stabilizing agent to prevent agglomeration of the droplets; and thereafter subjecting the suspension to polymerization conditions without high turbulence; the improvement which comprises employing in combination colloidal silica as the solid particle emulsifier, and a low molecular weight, non-ionic, water-soluble cellulose ether, having a viscosity grade of about 5 centipoise or less, as the stabilizing agent.