Direct Black 38

Application Features

Colour Fastness Test

Direct black BN alias direct black BX, direct black EX, direct black RN. Appearance is generally black uniform powder. Good water solubility, soluble in water, green and black, slightly soluble Alcohol is greenish blue-black, slightly soluble in cellosolve, insoluble in other organic solvents. It is dark red blue in concentrated sulfuric acid, reddish to red-black precipitate after dilution; red black in concentrated hydrochloric acid It is yellowish brown in concentrated nitric acid. Its aqueous solution is concentrated with hydrochloric acid and has a red precipitate. The concentrated sodium hydroxide has a grayish blue precipitate.

Used for cotton, viscose, silk, polyamide fiber and its blending fabric, leather, wood, biological and plastic color, also used as the raw material of black ink.

Use condition:

1. Direct black BN dyed cotton or viscose fiber is black, such as p-nitroaniline coupled with diazotization, the color is obviously greenish. Good dyeing, poor transferability, sensitive to salt, slow heating when dyeing And salt is added to control the dyeing to obtain uniform color. After dyeing, the dyeing solution should be naturally cooled to 80 °C, which is beneficial to the dye exhaustion.

2. Direct black BN has been used for dyeing rich fiber, good dyeing, and the dyeing rate is slightly higher than cotton. It has also been used for dyeing silk, wool and cotton, viscose fiber interlaced or blended fabric, dyed silk and wool can be added Yuanming powder. When dyeing vinyl fabric, the dyeing rate is still good, and the color light is slightly greener than cotton. When cotton, viscose fiber and other fibers are dyed in the same bath, silk and wool can be approximated to the depth of cotton and viscose fiber. With green light, if dyeing with low temperature, silk and wool will be close to white; nylon will be green and black, diacetate and acrylic will be brownish, and polyester will be light brown.

3. Direct Black 38 (Direct black BN) has been used for direct printing of cotton or viscose fabrics. It needs to be added with urea and disodium hydrogen phosphate to prepare color paste. When used for ground color discharge, it has better neutral dyeing effect. It can also be used for silk and silk. Printed wool fabric.

Precautions

Direct Black 38 contains a carcinogenic aromatic amine benzidine, which is a banned dye. The alternative dyes are C.I.Direct Black 22 and C.I.Direct Black 103.