AQUEOUS COMPOSITIONS FOR WHITENING AND SHADING IN COATING APPLICATIONS

Aqueous coating composition for optical brightening and shading of substrates comprising (a) at least one optical brightener of formula (I) in which the anionic charge on the brightener is balanced by a cationic charge composed of one or more identical or different cations selected from the group consisting of hydrogen, an alkali metal cation, alkaline earth metal, ammonium, ammonium which is mono-, di-, tri- or tetrasubstituted by a C1-C4 linear or branched alkyl radical, ammonium which is mono-, di-, tri- or tetrasubstituted by a C1-C4 linear or branched hydroxyalkyl radical, ammonium which is, di-, tri- or tetrasubstituted by a mixture of C1-C4 linear or branched alkylradical and linear or branched hydroxyalkyl radical or mixtures of said compounds, R1 and R1′ may be the same or different, and each is hydrogen, C1-C4 linear or branched alkyl, C2-C4 linear or branched hydroxyalkyl, CH2CO2−, CH2CH2CONH2 or CH2CH2CN, R2 and R2′ may be the same or different, and each is C1-C4 linear or branched alkyl, C2-C4 linear or branched hydroxyalkyl, CH2CO2−, CH(CO2−)CH2CO2−, CH(CO2−)CH2CH2CO2−, CH2CH2SO3−, CH2CH2CO2−, CH2CH(CH3)CO2−, benzyl, or R1 and R2 and/or R1′ and R2′, together with the neighboring nitrogen atom signify a morpholine ring and p is 0, 1 or 2, (b) at least one shading dye of formula (II) in which R3 signifies H, methyl or ethyl, R4 signifies paramethoxyphenyl, methyl or ethyl, M signifies a cation selected from the group consisting of hydrogen, an alkali metal cation, alkaline earth metal, ammonium, ammonium which is mono-, di-, tri- or tetrasubstituted by a C1-C4 linear or branched alkyl radical, ammonium which is mono-, di-, tri- or tetrasubstituted by a C1-C4 linear or branched hydroxyalkyl radical, ammonium which is, di-, tri- or tetrasubstituted by a mixture of C1-C4 linear or branched alkylradical and linear or branched hydroxyalkyl radical or mixtures of said compounds, (c) at least one white pigment, (d) at least one primary binder, (e) optionally one or more secondary binders and (f) water.