abstract |
This invention relates to a composition, comprising a) at least one quaternary ammonium compound of the formula (I) wherein R is a C 5 to C 21 aliphatic hydrocarbon group, X is an anionic counter ion, and R a , R b are selected from the group consisting of hydrogen, methyl, ethyl, allyl, propyl, butyl, phenyl or benzyl residues, b) ammonium bisulfite or sodium bisulfite, c) glutaraldehyde or THPS, and d) at least one organic dye. |