Direct Blue 15

Direct Blue 15 Appearance is generally blue uniform powder. Good water solubility, soluble in water, reddish blue, insoluble in organic solvents. 

It is blue-green in concentrated sulfuric acid, reddish blue after dilution; in concentrated nitric acid It is reddish gray. 

Its aqueous solution is concentrated with hydrochloric acid and has a red-blue precipitate. Concentrated sodium hydroxide has a purple precipitate. In case of copper ion, the color becomes dark.

TRADE NAME:Direct Sky Blue 5B,Direct Blue for paper,Direct Pure Blue,ACDI Sky 5B,Apollo Direct Sky Blue 5B,Atul Direct Sky Blue,Bitamine Direct Sky Blue FB,Blue 5BN,Concorde Direct Sky Blue 5B,Condirec Blue AE,Direct Fast Blue 5B,Direct Sky Blue FF

Key Features

• ‍High solubility in water for easy application
• Strong affinity to cellulose fibers
• Excellent wash and light fastness
• Uniform and bright coloration
• Suitable for industrial-scale textile dyeing
• Stable under moderate pH and temperature conditions‍

Technical Specifications

• ‍CAS NO: 2429-74-5
• CI.NO: 24400
• Molecular Formula:C34H24N6Na4O16S4
• Molecular Weight: 992.81
• Shade: blue powder, soluble in water solution for the red light blue‍

Application Features

Colour Fastness Test

Application:

Direct Blue 15 Mainly used for cotton, such as glue the cellulose fibre, silk and rayon / Kam fabric dyeing, also can be used for pulp, biological, film footage of dyeing, can also be used to make the ink.

Use condition:

• ‍1. It has been used to dye cotton or viscose fiber to get bright green blue, such as diazotization after dyeing, coloring with phenylmethylpyridone, which gives blue-green color. The dyeing rate is very good, shifting Dyeing and leveling are poor, it is advisable to add salt to control the dyeing to obtain uniform color. After dyeing, the dyeing solution should be naturally cooled to 60~80 °C, which is good for dye exhaustion.
• 2. It has been used to dye rich fiber, the dyeing rate is very good, but the color light is slightly darker than cotton. When dyeing vinyl fabric, the dyeing rate is poor, the color light is slightly bluer than the viscose fiber. Cotton, viscose fiber and When the other fibers are dyed in the same bath, the wool and nylon are gray, the silk is very light, the polyester and acrylic fibers are light yellowish gray, and the second vinegar fiber is not stained. When used for cold dyeing, the silk and wool are basically not stained.
• 3. Direct Blue 15 has also been used for direct printing of cotton or viscose fabrics. When printing dark patterns, it can be used to dissolve dyes in urea. When dyeing for ground color, the dyeing performance is good. After coloring, it was whitened with a stannous chloride reducing agent, and the whitening effect was good.
• 4. It was once one of the main blue direct dyes. It is mainly used for dyeing and printing of viscose fabrics, cotton knits and fabrics such as flannel and velvet. It is also used in viscose fiber. Dyeing with nylon blend fabric‍

Precautions

Direct Blue 15 can decompose 3,3'-dimethoxybenzidine, which is a banned dye. The substitute dye is C.I.Direct Blue71.

FAQ

How should Direct Blue 15 be applied for best results?

The dye should be dissolved in warm water before adding to the textile bath. Maintain moderate pH levels and consistent temperature to achieve uniform coloration.

Does Direct Blue 15 require a mordant?

No mordant is needed. Direct Blue 15 adheres directly to cellulose fibers, simplifying the dyeing process and reducing chemical usage.

What is the lightfastness of Direct Blue 15?

It has good lightfastness, making it suitable for fabrics exposed to sunlight, though prolonged intense exposure may slightly fade the color.

Can Direct Blue 15 be mixed with other dyes?

Yes, it can be blended with other compatible direct dyes to achieve custom shades. Ensure compatibility to maintain colorfastness and avoid unwanted reactions.