GB634680A - Improvements in or relating to method of coagulating dispersions - Google Patents

Abstract

<PICT:0634680/IV (a)/1> Latices prepared by the polymerization of butadiene, isoprene, dimethyl butadiene or chloroprene with or without acrylonitrile acrylic esters, vinylidene chloride or styrene in aqueous emulsions are coagulated by continuously introducing flowing liquid streams of the dispersion and of a liquid coagulant into a coagulating region, turbulently intermixing to coagulate the dispersion and form an aqueous slurry containing small discrete crumbs of synthetic rubber surrounded by aqueous liquid, discharging the aqueous slurry into a further quantity of aqueous liquid to prevent agglomeration and finally separating the crumbs. The latices may contain emulsifying agents, e.g. soap, pigments, accelerators and age resistors. The coagulant may be dilute formic, acetic or sulphuric acid or alkali or alkaline earth chlorides or bisulphates. As shown, the dispersion and coagulant flow from tanks 1, 2 through pipes 3, 4 to coagulating region 5 and the coagulum flows into a receptacle 7 containing a non-coagulating liquid. In a modification, the two streams flowing from orifices impinge upon each other and in a further arrangement a stream of dispersion is introduced into the centre of a turbulently flowing annular stream of coagulant.