Solid fusible PVC additive aq. dispersion prepn. - by homogenising melt in aq. dispersant soln. in agitation zone and evacuating in to cold water

摘要

A process is claimed for prepg. a finely divided aq. dispersion of a homogeneous phase contg. a solid fusible material (I) and opt. a liquid material (II). The process comprises continuously subjecting to a high speed gradient, in an agitation zone, a mixt. obtd. by contacting an aqs. soln. of a dispersant and a melt of the homogeneous phase. The resp. temps. and feed rates of the aq. soln. and the melt are so adjusted that the dispersion formed is evacuated from the agitation zone before the melt reaches its solidification temp. The evacuated dispersion is then immediately (dis)continuously diluted with cold water at a temp. and in an amt. sufficient for the melt to solidify 300, pref. 60 secs. after evacuation of the dispersion from the agitation zone. The process gives a dispersion which is storage stable under agitation. It is partic. suitable for prepg. dispersions of stabilisers, plasticisers, lubricants, pigments, colourants and fillers used in conjunction with PVC.