Acid Red 249 is an anionic acid dye — a water-soluble, dark-red to magenta powder used for acidic dyeing of protein and polyamide fibres and for other soluble-dye applications.
Dark red powder, soluble in water, slightly soluble in ethanol for product red, the strong sulfuric acid for product red, diluted for pink; Join the hydrochloric acid solution for red; Add sodium hydroxide to brown. Metal ion to the colored light no effect.
Appearance is dark red powder. Soluble in water, slightly soluble in ethanol, magenta. In concentrated sulfuric acid, it is magenta, diluted to pink. The aqueous solution is red, hydrochloric acid is added red; sodium hydroxide is added to brown.
TRADE NAME:Weak Acid Brilliant Red B
Standard | Fiber | Soaping | Persperation Fastness | Oxygen bleaching | Light | |
Fading | Stain | |||||
AATCC | Wool | 4 | 3 | |||
ISO | Wool | 2 | 3 | 4 | 4 | 5 |
Leveling(grade) | Displacement | Whitening | Solubility(g/L) | Metal ion effect(grade) | ||
copper | iron | chromium | ||||
3~4 | C | well | 80(90℃) | 4 | 5 | 4 |
Test Methods | fiber | Alkali resistance | Carbonization | Chlorination discoloration | Oxygen bleaching | Alkali fluff | Acid fluff | potting | soaping | Perspiration | Sun exposure | ||||
discolor | Staining | discolor | Staining | discolor | Staining | discolor | Staining | ||||||||
AATCC | wool | 2 | 5 | — | 4 | 4 | 3 | — | — | — | — | — | — | — | 3 |
ISO | wool | 2~3 | 4 | 3~4 | 4 | 3~4 | 3 | 3~4 | 3~4 | 2 | 2 | 2 | 3 | 4 | 5 |
Used for wool, silk and polyamide fiber fabric dyeing and printing, but also for direct dyes and with bath dyeing wool/rayon blended fabric.
7. Metal ions have no effect on shade.
Used for dyeing and printing wool, silk, nylon/polyamide, some paper and specialty polymer/thermoset/thermoplastic formulations where soluble acid dyes are appropriate. Suitable for textile wet-processing and selected industrial coloration tasks.
Acid Red 249 performs best on protein fibers (wool, silk) and polyamides (nylon) under acidic dyebath conditions—these substrates produce strong, even shades. It is not recommended for most cellulose-based fibers (cotton) unless used with a suitable mordant or as a combined printing system; direct cellulose dyeing will give poor exhaustion and fastness compared to reactive or direct dyes.
For level dyeing on nylon/wool, acidic pH (pH 4–5, adjusted with acetic or formic acid) is common; operating temperatures range 60–95°C depending on fiber and process. Typical on-weight-of-fiber (OWF) lab shades are 0.5–2.0% for sample panels and ~1% OWF for general shade starts — but always validate with trials, as liquor ratio, auxiliaries and substrate influence uptake. Some supplier TDS list OWF ≈ 1.0 for production references.
The dye is pH-sensitive: concentrated strong acid can shift the shade toward magenta, while strong alkali may darken or cause browning/precipitation. Several sources report that common metal ions have limited effect on shade, but precipitation can occur if incompatible chemicals (e.g., certain cationic polymers or basic dyes) are present — perform compatibility trials before scale-up.
Fastness depends on fiber and after-treatment. Supplier data and product pages commonly report moderate to good wash fastness and variable light fastness (often quoted as acceptable for indoor textiles and many industrial uses). For outdoor or heavy-wear applications, run controlled fastness tests and consider steps like leveling agents, good rinsing and suitable finishing to improve performance.
Yes — there are commercial formulations that use soluble acid dyes for coloring certain thermosets/thermoplastics and paper, but heat stability and migration must be checked. Acid Red 249 will not behave like a pigment (it’s soluble), so evaluate bleed, migration and thermal stability under your processing conditions before adoption.
Handle as you would other dye powders: avoid inhalation and contact with skin/eyes; use appropriate PPE (mask, gloves) and local exhaust when weighing. Store sealed in a cool, dry place away from direct sunlight and moisture to maintain strength.
