Direct Yellow 12

Direct Yellow 12 alias directly frozen yellow GX, straight after brilliant yellow 4 r. Appearance is a deep yellow uniform powder. Soluble in water, yellow to golden yellow, the solubility of 30 G/L. 2% dye aqueous solution into frozen gel in the below 15 ℃. Slightly soluble in alcohol is green light yellow, slightly soluble in soluble fiber and acetone. A red light purple in the sulfuric acid, dilute purple to red light blue after precipitation. The aqueous solution of sulfuric acid precipitation in deep fast bordeaux, add sodium hydroxide precipitation golden orange, a slightly discolored in 10% sodium hydroxide solution.

TRADE NAME:Chrysophenine GX,Direct Yellow GX,Benzol Yellow LG,Direct frozen yellow G,Direct Yellow G,Direct Yellow 4R,Pyrazol Yellow,Chrysophenin NS

Technical Specifications

• ‍CAS NO: 2870-32-8
• CI.NO: 24895
• Molecular Formula: C30H26N4Na2O8S2
• Molecular Weight: 680.66
• Shade: red light yellow. Deep yellow evenly powder.‍

Colour Fastness Test

Application:

Direct Yellow 12 Most suitable for dyeing of viscose like cotton, flax, viscose rayon, acetate and jute, also for Ink, Leather and Paper coloration.

Use condition:

• ‍1.It for cotton or viscose fiber dyed red light yellow, has the good dye migration performance and levelness, glue of uneven quality silk and cotton covering power. High dyeing rate, dyeing stage after dyeing appropriate natural cooling to 40 ℃, is conducive to dye absorbs.
• 2.Direct Yellow 12 in with acetic acid assisted dyeing conditions, can be used in the dyeing of polyamide fabric. In neutral bath and acetic acid bath can also be used for the dyeing of silk and wool dyeing wool when the additive sodium sulphate accelerating. Dye whalen, dyeing rate, color dye than viscose fiber reddish. Cotton or viscose fiber and other fibers with bath dyeing, silk and wool and cotton and viscose fiber is the depth of the approximation, but wool color is a bit dark, both vinegar fibre, polyester, acrylic, not color. Can be used to glue the silk and silk fabric dyeing, dyeing and alkaline rhodamine often used in two steps or two bath dyeing, color is very bright double color can be obtained.
• 3.It can be used for the direct printing of cotton and viscose fiber fabrics. Urea must be added to facilitate the dissolution of deep and dense colors, and it can also be used as the ground color of discharge printing. It can also be used for the direct printing of silk fabrics and discharge of ground color, in the same way as cotton and viscose fiber fabrics.
• 4.It is widely used, often with direct green B and direct acid-resistant red 4BS color spell, but the amount should not be too high, Otherwise, it will affect the fastness to wet treatment. Generally, this product is only used for dyeing and printing knitwear, flannelette and blanket on cotton fabrics.‍

FAQ

What fibers is Direct Yellow 12 best suited for?

Direct Yellow 12 is primarily formulated for cellulosic fibers such as cotton and viscose. It also performs on cotton/polyester blends where a cellulosic component dominates. Results on protein fibers (wool, silk) are limited and typically require special auxiliaries.

How is Direct Yellow 12 normally applied — any typical recipe?

In exhaust (batch) dyeing, a typical starting recipe is 1–3% o.w.f. dye on dry fabric, with 20–60 g/L common salt (to promote exhaustion) and a neutral to slightly alkaline pH. Temperature is often raised gradually to 80–95°C for full shade development. Rinse thoroughly and follow with a mild soaping or fixation rinse to maximize wet fastness.

How can I alter the shade or make it greener/warmer?

Shade tuning is usually done by blending with other yellow dyes (for warmer tones) or small additions of blue/green direct dyes to shift toward green. pH and temperature also affect hue slightly—higher pH or stronger alkali can shift the perceived tone. Conduct small lab trials before scaling.

What fastness performance can I expect and how to improve it?

Direct Yellow 12 typically shows moderate wash and light fastness suitable for interior textiles and garments with routine care. Fastness improves with thorough rinsing, proper soaping/fixation after dyeing, and by avoiding excessive bleaching or harsh alkali. For higher wet-fastness requirements, consider after-treatments (e.g., appropriate cationic fixatives) validated at lab scale.

Are there compatibility or dyeing problems to watch for?

Common issues include spotting or unevenness from inadequate dispersion or insufficient leveling auxiliaries. High salt concentrations without good agitation can cause local over-exhaustion. Always pre-dissolve dye thoroughly, use proper levellers for difficult fabrics, and run a small pilot to adjust liquor ratios and auxiliaries.

Safety, handling and wastewater considerations?

Handle the powder or concentrated solutions with appropriate PPE (gloves, eye protection, dust control). Store in a cool, dry place away from strong oxidants. Wastewater from dyeing baths should be treated according to local regulations — typical measures include pH adjustment, adsorption/filtration, and biological treatment. Work with your effluent specialist to meet discharge limits.

How should I store Direct Yellow 12 and what is its shelf life?

Store in a sealed container in a cool, dry, well-ventilated area protected from direct sunlight and moisture. Under recommended storage conditions, most direct dyes are stable for 1–3 years; verify with your supplier’s certificate of analysis for exact shelf life.