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AssigneeNorth Carolina State University
InventorsHarold S. Freeman, Abraham Reife, Jolanta Sokolawska-Gajda
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Disclosed is an original approach to solving the environmental problem associated with the use of Cr-based metallized azo dyes to deliver black shades on natural and synthetic substrates. This invention affords methods for both the synthesis of metallized dyes and the generation of black dyeings using those dyes without employing metals designated as priority pollutants at any stage in either method. The key element of the disclosure is the use of black 1:2 Fe complexes of azo dyes in lieu of currently used Cr-based complexes which are based on environmentally unfriendly priority pollutant metals without compromising the desirable high fastness properties of the latter complexes, an accomplishment heretofore assumed unachievable.
A method of dying natural and synthetic substrates black comprising dyeing a substrate with an Fe complexed azo dye, wherein said Fe complexed azo dye comprises an environmentally safe black 1:2 Fe complexed azo dye of the formula ##STR24## where X is H or NHCOR, R is C.sub.1-6 alkyl, C.sub.1-6 alkoxy, or C.sub.1-6 hydroxyalkyl, Y is OH, NH.sub.2, N(C.sub.1-6 alkyl).sub.2, NH(C.sub.1-6 alkyl), or C.sub.1-6 alkyl, and A is H, K, Na, or NH.sub.4, and whereby said method is an environmentally safe method.
A method of dyeing natural and synthetic substrates black comprising dyeing a substrate with an Fe complexed azo dye, wherein said Fe complexed azo dye comprises an environmentally safe black 1:2 Fe complexed azo dye of the formula ##STR27## where X is H or NHCOR, R is C.sub.1-6 alkyl, C.sub.1-6 alkoxy, or C.sub.1-6 hydroxyalkyl, Y is OH, NH.sub.2, N(C.sub.1-6 alkyl).sub.2, NH(C.sub.1-6 alkyl), or C.sub.1-6 alkyl, and A is H, K, Na, or NH.sub.4, wherein said method is free of Cr ions and Cu ions, and whereby said method is an environmentally safe method.
A method of making a black colored dye useful for dyeing natural and synthetic substrates, said method comprising (1) diazotization of 1-hydroxy-2-aminobenzene, wherein the benzene moiety is substituted with SO.sub.2 Y in the 4-position or the 5-position, (2) coupling the resultant with 7-naphthol, wherein the naphthol moiety is substituted with X in the 1-position, to create an unmetallized dye, (3) converting said unmetallized dye to a 1:2 Fe complex using a Fe salt at a pH of about 8 or less, and then (4) salting out said metallized dye by precipitating with A+ ions, where X is H or NHCOR, R is C.sub.1-6 alkyl, C.sub.1-6 alkoxy, or C.sub.1-6 hydroxyalkyl, Y is OH, NH.sub.2, N(C.sub.1-6 alkyl).sub.2, NH(C.sub.1-6 alkyl), or C.sub.1-6 alkyl, and A is H, K, Na, or NH.sub.4, whereby there results an environmentally safe black 1:2 Fe complexed azo dye of the formula ##STR28## where X is H or NHCOR, R is C.sub.1-6 alkyl, C.sub.1-6 alkoxy, or C.sub.1-6 hydroxyalkyl, Y is OH, NH.sub.2, N(C.sub.1-6 alkyl).sub.2, NH(C.sub.1-6 alkyl), or C.sub.1-6 alkyl, and A is H, K, Na, or NH.sub.4, and whereby said method is an environmentally safe method.
A method of making a black colored dye useful for dyeing natural and synthetic substrates, said method comprising (1) diazotization of a 1-hydroxy-2-aminobenzene, wherein the benzene moiety is substituted with SO.sub.2 Y in the 4-position or the 5-position, (2) coupling the resultant with a 1-substituted 7-naphthol, wherein the naphthol moiety is substituted with X in the 1-position, to create an unmetallized dye, (3) converting said unmetallized dye to a 1:2 Fe complex using a Fe salt at a pH of about 8 or less, and then (4) salting out said metallized dye by precipitating with A+ ions, where X is H or NHCOR, R is C.sub.1-6 alkyl, C.sub.1-6 alkoxy, or C.sub.1-6 hydroxyalkyl, Y is OH, NH.sub.2, N(C.sub.1-6 alkyl).sub.2, NH(C.sub.1-6 alkyl), or C.sub.1-6 alkyl, and A is H, K, Na, or NH.sub.4, whereby there results an environmentally safe black 1:2 Fe complexed azo dye of the formula ##STR31## where X is H or NHCOR, R is C.sub.1-6 alkyl, C.sub.1-6 alkoxy, or C.sub.1-6 hydroxyalkyl, Y is OH, NH.sub.2, N(C.sub.1-6 alkyl).sub.2, NH(C.sub.1-6 alkyl), or C.sub.1-6 alkyl, and A is H, K, Na, or NH.sub.4, wherein said method is free of Cr ions and Cu ions and whereby said method is an environmentally safe method.
An Fe complexed azo dye useful for dyeing natural and synthetic substrates, said Fe complexed azo dye comprising a black 1:2 Fe complexed azo dye, wherein said Fe complexed azo dye is environmentally safe and wherein said Fe complexed azo dye has a lightfastness property in the dyeing of substrates, comparable to that property in a black 1:2 Cr complexed azo dye, which is based on an environmentally unsafe priority pollutant.
A dyed substrate comprising a substrate dyed with a Fe complexed azo dye, wherein the Fe complexed azo dye comprises an environmentally safe black 1:2 Fe complexed azo dye of the formula ##STR34## where X is H or NHCOR, R is C.sub.1-6 alkyl, C.sub.1-6 alkoxy, or C.sub.1-6 hydroxyalkyl, Y is OH, NH.sub.2, N(C.sub.1-6 alkyl).sub.2, NH(C.sub.1-6 alkyl), or C.sub.1-6 alkyl, and A is H, K, Na, or NH.sub.4, said dyed substrate having a lightfastness property comparable to that property in a substrate dyed at a substantially similar depth with a black 1:2 Cr complexed azo dye, which is based on an environmentally unsafe priority pollutant.
Dependencies are inferred from the claim text.