An ink jet textile printing ink composition according to the invention contains Li.sup.+, Na.sup.+, and a compound represented by the following formula (1):

##STR00001##

An ink jet textile printing ink composition according to the invention contains Li.sup.+, Na.sup.+, and a compound represented by the following formula (1):

##STR00001##

An ink jet textile printing ink composition according to the invention contains Li.sup.+, Na.sup.+, and a compound represented by the following formula (1): ##STR00001##

An ink jet textile printing ink composition according to the invention contains Li.sup.+, Na.sup.+, and a compound represented by the following formula (1): ##STR00001##

A reactive black dye composition is disclosed, which comprises: (A) a reactive blue dye represented by the following formula (I) or a salt thereof; and (B) a reactive red dye or a salt thereof, a reactive yellow dye or a salt thereof, or a combination thereof.

##STR00001##

Herein, R.sub.11, X.sub.1, X.sub.2, X.sub.31, X.sub.41 and n are defined in the specification. In addition, a method for dying fibers using the aforesaid reactive black dye composition is also disclosed.

The present invention is related to a novel high fixation ink composition for digital textile printing, which comprises: (A) at least one reactive dye compound with two reactive groups in an amount of 1% to 50% by weight; (B) an organic buffer in an amount of 0.05% to 10% by weight; (C) a humectant in an amount of 10% to 50% by weight; and (D) a solvent in remaining amount. When the aforesaid ink composition is applied in digital textile printing, fixation rate of dye on fabrics is high.

The present invention is related to a novel high fixation ink composition for digital textile printing, which comprises: (A) at least one reactive dye compound with two reactive groups in an amount of 1% to 50% by weight; (B) an organic buffer in an amount of 0.05% to 10% by weight; (C) a humectant in an amount of 10% to 50% by weight; and (D) a solvent in remaining amount. When the aforesaid ink composition is applied in digital textile printing, fixation rate of dye on fabrics is high.

Disclosed are reactive dyes and preparation methods thereof. The reactive dye may be prepared using heterocyclic primary amine as a diazo component, 4,4-diamino-2,2-stilbenedisulfonic acid, s-triazine, or ethylenediamine as a bridging group, and a dimonochlortriazine group as an active group. The color-changing compound is covalently bonded into the fiber chemical structure by nucleophilic substitution reaction between monochlorotriazine and the hydroxyl group in a textile structure, and the size of the conjugated system and the range of electron delocalization of the dye are changed by a reversible isomerization reaction of the hydroxyl group adjacent to the diazo group and the diazo group under different pH regulations. Moreover, the dye has a double color changing structure, which improves the capability of the dye combined with H/OH. The pH value range that can cause color changes in the dye is effectively expanded to include weak alkali, weak acid or even neutral conditions.