U.S. 8,211,504 B2
BASF Coatings has been granted a patent for a process for producing a color and/or effect coating system on a substrate comprised of one of a process comprised of applying at least one aqueous color and/or effect solid-color topcoat material to the substrate, to give at least one solid-color topcoat film, and curing the at least one aqueous solid-color topcoat film, to give at least one color and/or effect solid-color topcoat; and a process comprised of applying at least one aqueous color and/or effect basecoat material to the substrate, to give at least one aqueous basecoat film, at least one of flashing off and drying the at least one aqueous basecoat film, without curing it fully, applying at least one clearcoat material to the at least one aqueous basecoat film, to give at least one clearcoat film, and jointly curing the at least one aqueous basecoat film and the at least one clearcoat film, to give a multicoat color and/or effect coating system comprised of at least one color and/or effect basecoat and at least one clearcoat. The at least one color and/or effect aqueous basecoat material or the at least one aqueous color and/or effect solid-color topcoat material is comprised of at least one ionically and/or nonionically stabilized polyurethane binder that is one of saturated and unsaturated, and optionally grafted with olefinically unsaturated compounds, and at least one water vapor permeability adjusting additive, in an amount sufficient to prevent popping marks in the solid-color topcoat or basecoat, comprised of at least one of at least one aqueous dispersion of at least one copolymer prepared by a process comprised of subjecting at least one olefinically unsaturated monomer to free-radical polymerization in the presence of at least one water-insoluble initiator in an aqueous dispersion of at least one polyurethane resin having a number-average molecular weight Mn of from 1,000 to 30,000 daltons and containing on average per molecule from 0.05-1.1 polymerizable double bonds, the weight ratio between the at least one polyurethane resin and the at least one olefinically unsaturated monomer being between 1:10-10:1; and at least one aqueous dispersion prepared by a process comprised of dispersing and homogenizing a mixture of at least one hydrophobic polyurethane resin, at least one olefinically unsaturated monomer, at least one surface-active substance, and water in a high shear field to give stabilized particles of materials in the mixture in an aqueous phase, (co)polymerizing the at least one olefinically unsaturated monomer within these particles to give a dispersion of a hydrophobically modified core polymer, adding a mixture of at least one olefinically unsaturated monomer comprising at least one hydrophilic olefinically unsaturated monomer to the dispersion of the hydrophobically modified core polymer, an copolymerizing the at least one hydrophilic olefinically unsaturated monomer in the presence of the core polymer, to give a hydrophilic shell polymer, wherein the at least one aqueous color and/or effect solid-color topcoat material or the aqueous color and/or effect basecoat material contains no metal flake pigments, and which after curing gives a color and/or effect solid-color topcoat or color and/or effect basecoat having a water vapor permeability that is one of 60° C >6.0 mg/h·m·bar and p60° C >286.4 g·100 μm/m2·d, where d stands for day; or  the at least one aqueous effect or color and effect solid-color topcoat material or aqueous effect or color and effect basecoat material is comprised of metal flake pigments, and which after curing gives an effect or color and effect solid-color topcoat or an effect or color and effect basecoat having a water vapor permeability that is one of 60° C>4.0 mg/h·m·bar and 60° C>190.92 g·100 μm/m2·d, wherein the water vapor permeability of the at least one color and/or effect solid-color topcoat or the at least one color and/or effect basecoat is determined by ASTM F1249; and the at least one solid-color topcoat or the at least one color and/or effect basecoat has a film thickness of 25 to 70 μm and is free from popping marks after curing.