US Patent 8008394 Low-VOC primer for plastic coating

The invention is directed to coating compositions for direct coating of plastic substrates, comprising the following components:A) a hydroxy-functional binder component, comprising at least one branched hydroxy-functional polyester having a hydroxyl value of 50-300 mg KOH/g solid, a polydispersity of <2 and a number average molecular weight (Mn) of 300 to 4000, having at least three branches, and having at least one hydroxyl group on each of the at least three branches,B) a crosslinking component for the hydroxyfunctional binder component A),C) at least one adhesion promoting component and optionally,D) organic solvents, additives conventionally found in paints as well as pigments and/or fillers.