Acid Red 73 is a water-soluble acid dye formulated for dyeing and tinting protein and polyamide fibers (e.g., wool, silk, nylon) and for specialty uses in paper, leather, and some aqueous ink systems. It produces vivid red shades, is applied from acidic baths, and is valued where bright, clear red tones and good dyeing uniformity are required.
TRADE NAME:Acid Scarlet FGR,Acid Brilliant Red MOO
Acid Red 73 apperance is Yellow light red powder. Soluble in water red solution, soluble in ethanol and soluble fiber element, soluble in acetone, insoluble in other organic solvents. Meet strong sulfuric acid is red purple, diluted red brown in precipitation; Nitric acid in a blue, orange and brown to olive. Its water solution and strong hydrochloric acid generation dark red brown precipitation; Add sodium hydroxide solution generation dark brown precipitation. In dyeing copper and iron ions are darker color. Discharge the gender is good.
Standard | Fiber | Soaping | Persperation Fastness | Oxygen bleaching | Light | |
Fading | Stain | |||||
AATCC | Wool | 4 | 4 | 1 | 2 | 5 |
ISO | Wool | 3 | 5 | 3 | 1 | 6 |
Mainly used for wool, silk, paper and leather dyeing. Can also be used for plastic, wood, spices, electrical-controlled aluminum, medicine color. Can make the ink, the heavy metal salt can be used as pigment.
Acid Red 73 performs best on protein fibers such as wool and silk and on polyamide (nylon). On wool and silk you’ll get deep, saturated red tones; on nylon expect similar shades but often with slightly improved wash fastness. It is not recommended for cellulose fibers unless used with a suitable carrier or mordant system.
For most exhaust dyeing processes aim for pH 3.5–5.5. Protein fibers are commonly dyed at 40–60°C, while nylon often requires 60–95°C for full uptake. Keep pH stable during the critical uptake window and use a gentle ramp to temperature to improve leveling and avoid patchiness.
Lightfastness is intrinsic and usually moderate; to improve it consider mixing with more lightfast red shades or apply UV-stabilizing after-treatments. For washfastness, use cationic fixing agents, acid after-baths, or mild crosslinking agents recommended for the fiber type. Always trial at lab scale before plant implementation.
Acid Red 73 is compatible with most standard acid-dye auxiliaries (leveling agents, wetting agents, sequestering agents). Avoid strong oxidizing agents in the dye bath and test compatibility when using unusual cationic softeners or heavy metal salts, which can shift shade or reduce uptake.
Use the granulated or pre-solubilized form when possible. If using powder, pre-dissolve in warm water with gentle stirring to create a concentrated stock solution, then add slowly to the main liquor under agitation. For automated dosing, keep the stock at moderate agitation and monitor concentration to avoid localized overdosing.
Handle with standard chemical safety procedures (gloves, goggles, avoid inhalation of dust). Waste streams containing residual dye should be treated—apply coagulation/adsorption or biological treatments depending on local regulations. Follow local discharge limits and consider dye-specific wastewater tests to confirm treatment effectiveness.
Yes — it mixes well with other acid dyes to create nuanced red and orange shades. When formulating, match application conditions (pH, temperature, fiber) and perform bench trials to evaluate shade shift and fastness interactions. Keep a small sample record of dye blend recipes for reproducibility.
Store in a cool, dry place in tightly sealed containers. Protect from moisture and strong oxidants. Under proper storage conditions most dry acid dyes remain stable for 2–3 years; always check for caking or discoloration before use and run a small quality dyeing test if storage is prolonged.
