Coatings based on thermoplastic polyesters with addition of an unsaturated polyester as additive resin

A coating formulation comprising:

• A) a thermoplastic base polyester consisting of the copolymerization product of at least one aliphatic, cycloaliphatic and/or aromatic polybasic acid and/or anhydride thereof or at least one hydroxycarboxylic acid or derivative thereof and at least one diol;
• B) an unsaturated additive polyester resin prepared by condensing at least one unsaturated dicarboxylic acid and optionally at least one saturated dicarboxylic acid monomer with at least one diol and/or triol, wherein the proportion of unsaturated additive polyester to base polyester ranges from 0.1-15 parts to 99.9-85 parts;
• C) at least one substance selected from the group consisting of color pigments, fillers, stabilizers, leveling agents and luster agents;
• and
• D) a third polyester formed by reacting:
• a) at least one aromatic dicarboxylic acid and at least one aliphatic dicarboxylic acid of 2-36 atoms, or ester-forming derivatives thereof, and
• b) 1,4-butanediol, or 1,4-butanediol with at least one aliphatic diol having 2-36 carbon atoms, wherein
• the third polyester has a glass transition temperature ranging from -50 to 0.degree. C. and a melting range of 140-200.degree. C., and
• the third polyester is incorporated in the coating formulation in an amount of from 2-60% by weight, based on the overall coating formulation.