Abstract: The adhesion, especially wet adhesion, properties of conventional polymer latices are greatly improved by the incorporation of groups derived from the reaction of carbonyl groups with hydrazines therein. The hydrazine-modified groups can be present in any component of the polymer latex, but are advantageously part of the main polymer itself. Preferred main polymers are therefore those containing carbonyl units capable of reacting with hydrazine or a substituted hydrazine, especially copolymers of N-3-oxyhydrocarbon-substituted acrylamides such as diacetone acrylamide. Significantly improved wet adhesion properties are obtained even with very low proportions of the hydrazone-modified groups.