A process for the production of a copolymerizate containing:(a) from 10% to 30% by weight of ethylene monomeric units, (b) from 29% to 69% by weight of monomeric units of an acrylic acid ester of an alkanol having from 4 to 12 carbon atoms, (c) from 20% to 55% by weight of vinyl acetate monomeric units, (d) from 0.2% to 8% by weight of monomeric units having the formula: ##STR7## wherein R' is a m