With the binder produced according to the invention, a number of coating products can be produced which adhere to plastics directly and without any chemical or physical pretreatment. Base coats, high-gloss lacquers, metallic lacquers, clear lacquers and effect lacquers can be produced which can be applied directly on plastics; this is an absolute novelty because pretreatment is no longer required. With the binder according to the invention it is also possible to formulate adhesives which guarantee very good bonding between plastics themselves and also paperboard packaging. The invention relates to the binder as well as base coats based on them, one-coat lacquers and adhesives.