Method of manufacturing a waterproof dye layer on a substrate and substrate comprising a dye layer.

摘要

A method of manufacturing a homogeneous, waterproof dye layer on a substrate is provided in which a solution of a cationic or anionic dye in an organic solvent is provided on the substrate, the solvent is removed and the resulting dye layer is treated with an aqueous solution of a salt in which the cation of the anionic dye is exchanged against the cation of the salt or is treated with a salt or acid in which the anion of the cationic dye is exchanged against the anion of the salt or acid. The invention also provides a substrate comprising a waterproof homogeneous dye layer.