The development of pressure polymers for emulsion paints

“Pressure polymers” is a convenient short name for vinyl acetate‐ethylene, and vinyl acetate‐ethylene‐vinyl chloride copolymers; the use of ethylene in particular necessitates operating the polymerisation reaction at appreciable pressures, in some cases up to 200 atm. However, the use of pressure in emulsion polymerisation is not an end in itself, interesting though the chemical and engineering challenge has proved to be: the development has arisen from the search for paint media with the best balance of cost and efficiency. Our first experimental vinyl acetate‐ethylene emulsions were shown at the 1966 OCCA Technical Exhibition; one of these grades has been in use on a limited scale for some years, and is now in bulk production at our Warrington factory, which began operating in October 1974. We subsequently undertook work on copolymers and terpolymers involving vinyl chloride, and bulk production of selected products has now started at Warrington.