US Patent 7442731 Opaque, colour-pigmented coating

The invention relates to a coating having a thickness of from 5 to 25 μm, comprising a high-molecular-weight organic material and from 5 to 9 g/m2 colored pigments, wherein, based on the total amount of colored pigments, (a) from 30 to 90% by weight of 3,6-di(4′-biphenyl)-2,5-dihydro-pyrrolo[3,4-c]-pyrrole-1,4-dione having a specific surface area of from 20 to 50 m2/g and (b) from 10 to 70% by weight of a further organic colored pigment, selected from the series consisting of quinacridone, diketo-pyrrolo[3,4-c]-pyrrole, dioxazine, indanthrone, perylene, phthalocyanine and 3-amino-1H-isoindol-1-one-oximatometal complex pigments and solid solutions and mixtures thereof, are present.