abstract |
A process is disclosed for obtaining coating compositions of improved whiteness for coating paper or cardboard using fluorescent whitening agents of the bis-triazinylaminostilbene-2,2'-disulfonic acid series, which process comprises adding to the coating compositions, in addition to the respective fluorescent whitening agent, an acid phosphoric acid ester of an oxyalkylated fatty amine of the formula ##STR1## or an alkali metal salt, ammonium salt or amine salt thereof, wherein R is an aliphatic hydrocarbon radical of 8 to 22 carbon atoms, Y 1 and Y 2 are both hydrogen, or one of Y 1 and Y 2 is hydrogen and the other is methyl, X is the acid radical of phosphoric acid, the acid hydrogen atoms of which radical can be replaced by alkali metal ions, ammonium ions or amine salt ions, and m and n are integers, the sum of which is 2 to 30. To the coating compositions can also be added organic solubilizers, non-ionic or anionic surfactants and/or polar organic compounds. Coating compositions which contain the above fluorescent whitening agents and assistants are also disclosed. |