Direct Blue 6

Application Features

Direct blue 2B alias direct indigo, direct indigo 2B. Appearance is generally dark blue uniform powder, good water solubility. Dissolved in water blue to navy, slightly soluble in alcohol and cellosolve, insoluble in other organic solvents. It is bright blue in sulfuric acid, turns purple to red blue after dilution, reddish brown in concentrated nitric acid, blue-violet in concentrated sodium hydroxide, red blue in concentrated ammonia, and concentrated hydrochloric acid in aqueous solution. There is a navy blue precipitate, and the concentrated sodium hydroxide has a deep purple precipitate. When the copper and iron ions are turned, the color turns red.

Mainly used for cotton, such as glue the cellulose fibre, silk and their blended fabric, pulp and biological dyeing.

Use condition:

1. Direct Blue 6 has been used for dyeing cotton or viscose fiber to obtain cyan blue. For example, after diazotization, 2-naphthol is used to develop blue-violet gray color, and phenylmethylpyridone is used to develop green light gray. The dyeing rate is good, the dyeing property and leveling property are poor. When dyeing, salt should be added to control the dyeing to obtain uniform color. After dyeing, the dyeing solution should be naturally cooled to 40~80 °C, which is good for dye exhaustion. .

2. It has also been used for dyeing rich fiber, the dyeing rate is very good, the color light and dyeing cotton are similar. When dyeing vinyl fabric, the dyeing rate is poor, the color light is slightly darker than cotton. Cotton, viscose fiber and other fibers are the same. When dyeing the bath, the wool is light gray, the silk is very light, the nylon is heavily stained, the second vinegar is slightly stained, and the polyester and acrylic are light yellowish gray. If dyed at low temperature, the silk and wool are almost non-stained. .

3.It has also been used for direct printing of cotton or viscose fabrics, and it is necessary to add urea to dissolve the dark-colored paste.

When the ground color is discharged, the discharge performance is good.

Precautions

Direct Blue 6 can be used to decompose benzidine, which is a banned dye. The alternative dye is C.I.Direct Blue 71.