The polyolefin, eg. polyethylene, surfaces coated with the dicarboxylic acid dihydrazides and with the aqueous dispersions of adhesive polymers can be laminated with other substrates, eg. uncoated films based on polyolefins, nylons, polyesters, polystyrene or polyvinyl halides, in particular polyvinyl chloride, or can be adhesively bonded to other sheet-like substrates, for example those consistin