Process for improving washfastness of indigo-dyed fabrics

Claim 2

A process for fixing indigo dye on a cellulosic fiber substrate to improve the washfastness thereof comprising applying to an indigo-dyed substrate a fixing solution of: (1) a dihalo-s-triazine of the formula: ##STR6## wherein Y and Y' which are the same or different are selected from sulfonic, phosphonic, phosphoric or carboxylic groups, provided that one of Y or Y' may be hydrogen, and X is chlorine, fluorine or bromine; (2) a dihalo-s-triazine reactive dye of the formula: ##STR7## wherein Dye is a chromophore and X is as defined above; (3) a poly(halo-s-triazine) reactive dye of the formula: ##STR8## where each Dye, which represents a chromophore, may be terminally or internally bonded to one or more of the triazine rings; n is 1 or 2, m is 2 or 3, X is as defined above; and Z is at least one of X, NH, a non-colored bridging link which may be or include another triazine ring, or combinations of two or more of these: (4) a quaternary ammonium compound of the formula: ##STR9## wherein R 1 , R 2 , and R 3 , which are the same or different are C 1 -C 3 alkyl groups and X is as defined above; (5) mixtures of (1) and (2); or (6) mixtures of (1) and (3); at a pH of 7.0 to about 12, and thereafter curing the thus treated substrate.

Claim 3

The process according to claim 1 including the further step of heating the dried substrate to a temperature of about 220° F. to about 400° F. for a period of time sufficient to dry and cure the treated substrate.

Claim 4

The process according to claim 1 wherein the treated substrate is rolled, stored at ambient temperature of about 65° to 90° F., and cured on the roll.

Claim 5

The process according to claim 1, 2 or 3 wherein said substrate is a warp-dyed denim fabric.

Claim 6

The process according to claim 1 wherein the fixing solution is applied by padding, spraying or rolling onto said substrate.

Claim 7

An indigo-dyed blue denim fabric having improved washfastness produced by the process of claim 4.

Claim 8

In a process for producing cellulosic fabric containing indigo-dyed cellulosic fibers therein, comprising the steps of indigo dyeing a cellulosic fiber and weaving a portion of the thus dyed fiber into a fabric, the improvement of treating the indigo-dyed fabric to improve the washfastness thereof comprising the steps of: A. applying a solution of: (1) a dihalo-s-triazine of the formula: ##STR10## wherein Y and Y' which are the same or different are selected from sulfonic, phosphonic, phosphoric or carboxylic groups, provided that one of Y or Y' may be hydrogen, and X is chlorine, fluorine or bromine; (2) a dihalo-s-triazine reactive dye of the formula: ##STR11## wherein Dye is a chromophone and X is as defined above; (3) a poly(halo-s-triazine) reactive dye of the formula: ##STR12## where each Dye, which represents a chromophore, may be terminally or internally bonded to one or more of the triazine rings; n is 1 or 2, m is 2 or 3, X is as defined above; and Z is at least one of X, NH, a non-colored bridging link which may be or include another triazine ring, or combinations of two or more of these: (4) a quaternary ammonium compound of the formula: ##STR13## wherein R 1 , R 2 , and R 3 , which are the same or different are C 1 -C 3 alkyl groups and X is as defined above; (5) mixtures of (1) and (2); or (6) mixtures of (1) and (3); at a pH of 7.0 to about 12, to the fabric, and thereafter B. heating to dry and cure the thus treated fabric.

Claim 9

In a process for producing cellulosic fabric containing indigo-dyed cellulosic fibers therein, comprising the steps of indigo dyeing a cellulosic fiber and weaving a portion of the thus dyed fiber into a fabric, the improvement of treating the indigo-dyed fabric to improve the washfastness thereof comprising the steps of: A. applying a solution of: (1) a dihalo-s-triazine of the formula: ##STR10## wherein Y and Y' which are the same or different are selected from sulfonic, phosphonic, phosphoric or carboxylic groups, provided that one of Y or Y' may be hydrogen, and X is chlorine, fluorine or bromine; (2) a dihalo-s-triazine reactive dye of the formula: ##STR11## wherein Dye is a chromophone and X is as defined above; (3) a poly(halo-s-triazine) reactive dye of the formula: ##STR12## where each Dye, which represents a chromophore, may be terminally or internally bonded to one or more of the triazine rings; n is 1 or 2, m is 2 or 3, X is as defined above; and Z is at least one of X, NH, a non-colored bridging link which may be or include another triazine ring, or combinations of two or more of these: (4) a quaternary ammonium compound of the formula: ##STR13## wherein R 1 , R 2 , and R 3 , which are the same or different are C 1 -C 3 alkyl groups and X is as defined above; (5) mixtures of (1) and (2); or (6) mixtures of (1) and (3); at a pH of 7.0 to about 12, to the fabric, and thereafter B. heating to dry and cure the thus treated fabric.

Claim 10

The process according to claim 7 wherein a fabric size is applied prior to step (A).

Claim 11

The process according to claim 7 wherein a fabric size is applied after step (A).