Acid Red 336 (C.I. Acid Red 336, CAS 12239-11-1) is a water-soluble monoazo/azo acid dye that yields bluish-red to wine-red aqueous shades. It is supplied as a dark red/bluish-red powder and is commonly used for dyeing protein and polyamide fibres (wool, silk, nylon) and for leather, ink and paint applications due to good dispersion and reproducibility.
TRADE NAME:Acid Red MS-R,Red N-2RBL,Weak acid red MF-2BL
Appearance is dark red powder. Soluble in water, soluble in ethanol, red sauce. Dark blue in concentrated sulfuric acid, red wine after dilution. Aqueous solution is wine red, hydrochloric acid is reddish brown; sodium hydroxide is red sauce .
Standard | Fiber | Soaping | Persperation Fastness | Oxygen bleaching | Light | |
Fading | Stain | |||||
ISO | Wool | 2-3 | 2-3 | 5 | 5-6 | |
Leveling(grade) | Displacement | Whitening | Solubility(g/L) | Metal ion effect(grade) | ||
copper | iron | chromium | ||||
4 | — | well | 30(90℃) | — | — | — |
Test Methods | fiber | Alkali resistance | Carbonization | Chlorination discoloration | Steaming | Acid fluff | seawater | Soaping | Perspiration | Sun exposure | |||
discolor | Staining | discolor | Staining | discolor | Staining | ||||||||
ISO | wool | 5 | 4~5 | 5 | 5 | 3~4 | 2~3 | 5 | 4 | 2~3 | 2~3 | 5 | 5~6 |
Mainly used for sea of target that fluorescent, facilitate aerial reconnaissance search. And can use significantly for the exploration of fluorescent groundwater. Can also be used for medicine and cosmetics shading, rarely used for silk printing and dyeing things.
Reported fastness varies with substrate and recipe, but typical supplier data indicate good light fastness (often ISO 5–6) and moderate to good wash fastness (often ISO 4–5) when properly fixed and after standard finishing. Always run pilot trials under your specific process conditions.
Use conventional acid dyeing procedures: acidified aqueous bath, controlled temperature ramp to the dyeing temperature for the fibre (e.g., ~85–95°C for wool/nylon), appropriate leveling agents and pH control. Exact recipe (pH, temperature ramp, auxiliaries) should be optimized per fibre and equipment.
The dye is water-soluble (gives wine-red aqueous solutions) and shows characteristic colour changes in strong acids/bases (different tones in concentrated sulfuric acid or strong alkali). Solubility and tone shift are reported in supplier datasheets — handle concentrates and powder with standard precautions.
As with many azo acid dyes, follow standard industrial safety (dust control, PPE) and waste management practices. Consult the product MSDS for breakdown, biodegradability and regulatory details; some azo dyes require special wastewater treatment or monitoring depending on local discharge rules.
