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US 5,203,876 AGranted
Process for dyeing paper
AssigneeCiba-Geigy Corporation
InventorAdolf Kaser
Life of this patent
Estimating the term…
Abstract
The dyes of formula ##STR1## wherein R, M and n are as defined in claim 1, are preeminently suitable for dyeing paper in blue shades.
Claims10
A process for dyeing paper, which comprises contacting paper with a solid or liquid aqueous dye, wherein said liquid dye is substantially undissolved in the dyeing liquor, said dye being of the formula ##STR5## wherein R is hydrogen, --OH, --OR.sup.1, --NH.sub.2, --NHR.sup.1, --NHCOR.sup.1, --NHSO.sub.2 R.sup.1, --NHCONH.sub.2 or --NHCONHR.sup.1, in which R.sup.1 is unsubstituted or substituted alkyl or aryl, M is hydrogen or the equivalent of a colourless cation, and n is 1 or 2,
- and the --OH group in the .alpha.-position and the azo group in the .beta.-position of the naphthalene nucleus are mutually interchangeable.
Dependencies are inferred from the claim text.