Direct Blue 71

Application Features

Direct Blue 71 alias direct light blue B2RL, direct light blue B2R. The appearance is generally blue gray uniform powder. Water soluble, soluble in water blue, slightly soluble in cellosolve, very slightly soluble in alcohol, Insoluble in other organic solvents. The dye is blue to grayish black in concentrated sulfuric acid, red-violet purple precipitate after dilution; dark brown in concentrated nitric acid; insoluble in concentrated sodium hydroxide; blue-violet in concentrated ammonia. The aqueous solution added with concentrated hydrochloric acid has a blue precipitate, and the concentrated sodium hydroxide has a red-violet purple precipitate. The copper and iron ion shades slightly change.

Widely used in viscose fiber dyeing, also used in viscose/PVA blends, cotton, and the carpet of dyeing and printing. Also used in leather, paper, soap, cheese, protein and formaldehyde resin color.

Use condition:

1. The dyed cotton or viscose fiber has a reddish-dark blue color. The dyeing rate is good, the transferability and levelness are poor. When dyeing, it is advisable to add salt to control the dyeing to obtain uniform color. After the dyeing stage, the dyeing solution should be naturally cooled to 80 ° C, which is beneficial to the dye exhaustion. After dyeing, the color light micro green is finished by urea-formaldehyde resin, and the color is brightly changed to green by the cyanoaldehyde resin; the red color is treated by copper sulfate, and then the resin is finished. , its sun fastness is not affected.

2. Used for dyeing rich fiber, the dyeing rate is very good, the color light is slightly darker than cotton. It can also be used for dyeing silk and its fabric, dyeing bath plus Yuanming powder and acetic acid. When dyeing vinyl fabric, dyeing The rate difference is lighter than blue. When cotton, viscose fiber and other fibers are dyed in the same bath, the wool is lighter than cotton and viscose fiber, the silk is lighter, the nylon is heavily stained, the second vinegar fiber, the three vinegar fiber, the polyester fiber. Acrylic fiber is almost non-staining.

3. Direct Blue 71 can be mixed with disperse dye in high temperature dyeing and blending fabric. The dyeing bath is heated to 120 °C under neutral conditions, or loaded with boiling dye. After the dye is dyed with polyester, the temperature is continued. After dyeing for half an hour, the cellulose fibers are fully colored, and the dye is exhausted, and the color light is substantially unchanged.

4. Used for continuous padding of cotton. After padding, it is treated with 10~25g/L yuan powder boiling bath, then steamed at 100~103°C for 1-3 minutes.

5. Used for direct printing of cotton or viscose fabric. When printing deep pattern, add urea and disodium hydrogen phosphate to prepare the printing paste.