VERFAHREN ZUR KOAGULATION VON LATICES

摘要

In a process for the acid coagulation of polymer lattices, the latex is contacted with an (in)organic acid at 70-100 degrees C and a pH of 2-4 in a first vessel with intensive stirring. The reaction mixt. is then tranferred into >=1 further stirred vessel and stirred at the same temp. and pH, and after a total residence time of 2 mins. to 2 hrs., the resulting coagulate is sepd. The process is esp. useful for coagulating lattices of homo- or copolymers of butadiene, styrene and acrylonitrile contg. an anionic emulsifier, e.g. using H2SO4 as coagulation agent. Process can be carried out in conventional stirred vessels. Coagulation is achieved using relatively small amts. of acid, and the resulting coagulate has a relatively fine particle size (e.g. nearly equals 3mm.) which is well suited to further processing.