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US 5,677,434 AGranted
Iron-complexed formazan dyes for polyamide and protein substrates
AssigneeNorth Carolina State University
InventorsHarold S. Freeman, Jolanta Sokolowska-Gajda, Abraham Reife
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Abstract
A family of 1:2 Fe-complexed formazan dyes is described. The dyes unexpectedly afford reddish-violet, violet, blue and black shades on natural and synthetic substrates. Methods for synthesizing the dyes and for dyeing a substrate are described. The dyes represent environmentally friendly alternatives to conventional Cr- and Co-based azo and formazan dyes.
Claims12
A dye of the formula ##STR8## wherein X and X.sub.1 are independently O or COO;
- Y and Y.sub.1 are independently H, halogen, NO.sub.2, SO.sub.2 NH.sub.2, SO.sub.2 N(R.sub.1).sub.2, SO.sub.2 NH(R.sub.1), or SO.sub.2 (R.sub.1).sub.2, where R.sub.1 is C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 hydroxyalkyl, or C.sub.1 -C.sub.6 alkoxyalkyl;
- Z and Z.sub.1 are independently H, SO.sub.2 NH.sub.2, SO.sub.2 N(R.sub.1).sub.2, SO.sub.2 NH(R.sub.1), or SO.sub.2 (R.sub.1).sub.2 wherein R.sub.1 is C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 hydroxyalkyl, or C.sub.1 -C.sub.6 alkoxyalkyl, or R.sub.1 is SO.sub.3 M wherein M is H.sup.+, a metal ion, or NH.sub.4.sup.+ ;
- and
- A.sup.+ is H.sup.+, a metal ion, or NH.sub.4.sup.+.
1 more element
A dye of the formula:
- ##STR9## wherein X and X.sub.1 are independently O or COO, Y and Y.sub.1 are independently H, halogen, NO.sub.2, or SO.sub.2 NH.sub.2,
- Z and Z.sub.1 are independently H, SO.sub.2 NH.sub.2, or SO.sub.3 M, wherein M is H.sup.+, a metal ion, or NH.sub.4.sup.+, and
- A.sup.+ is H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, or NH.sub.4.sup.+.
A method of making a 1:2 Fe-complexed formazan dye comprising:
- diazotizing a 2-aminophenol or 2-aminobenzoic acid compound;
- coupling the diazo product with a benzaldehyde phenylhydrazone of the formula ##STR11## wherein Z is selected from the group consisting of H, SO.sub.2 NH.sub.2, SO.sub.2 N(R.sub.1).sub.2, SO.sub.2 NH(R.sub.1), SO.sub.2 (R.sub.1).sub.2, and SO.sub.3 M, where R.sub.1 is C.sub.1 -C.sub.6 alkyl, C.sub.1 -C.sub.6 hydroxyalkyl, or C.sub.1 -C.sub.6 alkoxyalkyl, and M is H.sup.+, a metal ion, or NH.sub.4.sup.+, thereby forming an unmetallized formazan;
- reacting the unmetallized formazan with an Fe salt in aqueous solution at a pH of about 8 or less to generate a 1:2 Fe-complexed formazan;
- and
- precipitating the 1:2 Fe-complexed formazan.
2 more elements
Dependencies are inferred from the claim text.