Patent ID: 8722150

Claim:
A process for the production of a dark-color multi-layer coating, comprising the successive steps: (1) applying an NIR-opaque coating layer A′ from a waterborne pigmented coating composition A to a substrate, (2) applying a coating layer B′ from a waterborne pigmented coating composition B onto the substrate provided with coating layer A′, (3) subjecting the coated substrate obtained in step (2) to a drying step, (4) applying a clear coat layer from a clear coat composition onto the coated substrate obtained in step (3), and (5) curing the coating layers applied in steps (1), (2), and (4) simultaneously; wherein both waterborne coating compositions A and B comprise aqueous microgel and sheet silicate, wherein the pigment content of coating composition A consists 90 to 100 wt. % of at least one aluminum flake pigment and 0 to 10 wt. % of at least one further pigment, which is selected in such a way that NIR-opaque coating layer A′ exhibits low NIR absorption, wherein the pigment content of coating composition B consists 50 to 100 wt. % of at least one black pigment with low NIR absorption and 0 to 50 wt. % of at least one further pigment, which is selected in such a way that coating layer B′ exhibits low NIR absorption and that the dark-color multi-layer coating exhibits a brightness L* (according to CIEL*a*b*, DIN 6174), measured at an illumination angle of 45 degrees to the perpendicular and an observation angle of 45 degrees to the specular, of at most 10 units, and wherein the sum of the respective wt. % equals 100 wt. %.