Direct Yellow 50 alias direct light fast yellow FR. Appearance is light yellow uniform powder. Very good water solubility, not sensitive to hard water, soluble in water golden yellow, slightly soluble in alcohol, insoluble in other organic solvents. It is magenta in color, and turns blue-green and has a blue precipitate after dilution. The aqueous solution is concentrated with concentrated nitric acid and has a purple precipitate. Concentrated sodium hydroxide has a gold-orange precipitate. The color of copper and iron ions is basically unchanged.
TRADE NAME:Direct Fast Yellow RS,Direct Yellow RS,Direct Fast Yellow FTF
Main Features
- Water-soluble azo dye with bright yellow shade
- Good leveling properties for uniform dyeing
- Suitable for cotton, viscose, silk, paper, and leather
- Applicable in both dyeing and printing processes
- Cost-effective colorant with strong fiber affinity
- Compatible with other direct dyes for shade adjustment
Technical Specifications
- CAS NO: 3214-47-9
- CI.NO: 29025
- Molecular Formula: C35H24N6Na4O13S4
- Molecular Weight: 956.82
- Shade: red light yellow
| Dyeing depth % | 2 |
| Insolubles % | 0.15 |
| Light Fastness | 5 |
| Washing Fatness | 2-3 |
| Rubbing fastness(dry) | 4 |
| Rubbing fastness(wet) | 3 |
Application Features
Solubility(g/L) | SDC classification | displacement(grade) | metal ion effect(grade) | discharge property(grade) | other features |
| | | copper | iron | neutral | basic | |
80 (97℃) | A | 4~5 | 5 | 5 | 5 | 4~5 | — |
Colour Fastness Test
sun exposure | soaping | flooding | perspiration | rubbing | ironing | acid and alkali resistant |
standard depth | 1/12 depth | original color change | white fiber stained | original color change | white fiber stained | original color change | white fiber stained | dry | wet | | sulfuric acid | acetic acid | soda ash |
6 | — | 1 | 1 | 2~3 | 1 | 3~4 | 1 | 4 | — | 4 | 1 | 1~2 | 2~3 |
Application:
Direct Yellow 50 Most suitable for dyeing of viscose like cotton, flax, viscose rayon, acetate and jute, also for Ink, Leather and Paper coloration.
Use condition:
- 1. THe dyed cotton or viscose fiber has bright red yellow color. It has good leveling and transferability. The dyeing rate is still good.
- 2. It is used for dyeing rich fiber, the dyeing rate and color light are similar to dyeing cotton. It is also used for dyeing silk fabric, adding yuan powder and acetic acid, and dyeing the silk fabric after dyeing. The color light is not affected. When the fabric is dyed, the dyeing rate is poor, and the color light is similar to that of the viscose fiber. When the cotton, viscose fiber and other fibers are dyed in the same bath, the wool is lighter than cotton and viscose, and the silk is more Light, nylon and cotton and viscose fiber have a similar depth, acrylic, polyester, diacetate, three vinegar fiber does not stain.
- 3. It can be mixed with disperse dye in the same bath at high temperature to dye polyester blending fabric. The dyeing bath is adjusted with ammonium sulfate to adjust the pH value, and it is heated to 120 ° C under neutral or slightly alkaline conditions, or loaded with boiling dye. After the disperse dye is dyed with polyester, it is cooled down for another half an hour to fully color the cellulose fibers to promote the dye exhaustion.
- 4. It can be used for continuous padding of cotton, steamed and dried at 100~103 °C for 1~2min after padding.
- 5.Direct Yellow 50 can be used for direct printing of cotton or viscose fabric, plus urea and disodium hydrogen phosphate to adjust the color paste. It can also be used for ground color discharge.
FAQ
How should Direct Yellow 50 be applied in textile printing?
It can be used directly in aqueous dye baths for printing or piece dyeing. Pre-treatment with a wetting agent improves penetration and color consistency. The dye maintains brightness even after prolonged processing.
What fastness properties does Direct Yellow 50 offer?
It provides good light fastness and moderate wash fastness, making it suitable for fabrics exposed to sunlight or frequent laundering. Its low tendency for bleeding ensures stable color performance.
Are there environmental considerations when using Direct Yellow 50?
While generally safe for industrial use, proper wastewater treatment is recommended to minimize environmental impact. It is advisable to follow local regulations for dye effluent disposal.
Can Direct Yellow 50 be mixed with other dyes?
Yes, it can be combined with compatible direct or reactive dyes to achieve custom shades. Testing is recommended to ensure color stability and uniformity before large-scale production.
