
Product Name: Acid Red 249 / Weak Acid Brilliant Red B
Color Index: C.I. 18134
CAS: 6416-66-6
Molecular Formula: C₂₉H₂₀ClN₃Na₂O₁₀S₃
Formula Weight: 748.11 g/mol
Synonyms: Prass Red B; Prass Brilliant Red B; Weakly Acid Brilliant Red A-B; Acid Brilliant Red P-5B; Acid Brilliant Red 2B; Weakly Acid Brilliant Red B;Tracid Brilliant Red B; Weak Acid Brilliant Red B; Acid Brilliant Red B; Milling Brilliant Red 2B; Polar Brilliant Red B; Sandolan Brilliant Red N-BG; Supranol Brilliant Red BB; Suminol Milling Brilliant Red B; C.I. Acid Red 249; C.I. 18134
Application:
Textiles (Wool, Silk, Nylon, Polyamide), Leather Finishing, Paper Dyeing, Printing Inks, Lake Pigments, Stationery Products, Household Cleaners, Detergents
1.Product Description
Achieve Brilliant Blue-Shade Reds with Acid Red 249 – The Premier Milling Acid Dye for High-Performance Textiles.
Acid Red 249, widely recognized as Weak Acid Brilliant Red B or Tracid Brilliant Red B, is a distinguished monoazo dye engineered specifically for applications demanding superior wet fastness combined with brilliant, clean red shades. Its sophisticated molecular architecture, featuring a complex sulfonated naphthalene core with chloro-phenoxy and tolylsulfonylamino substituents, creates a larger molecular structure characteristic of milling-type acid dyes.
What truly distinguishes Acid Red 249 is its exceptional balance of leveling and fastness properties. The dye exhibits a distinctive bluish-red shade with maximum absorption at 523 nm in aqueous solution, producing vibrant, clean reds with excellent brightness. Its weak acid character allows for controlled exhaustion on protein and polyamide fibers while maintaining the high wet fastness required for apparel, swimwear, and upholstery applications.
The dye demonstrates remarkable stability in acidic dye baths (pH 4.5-5.5 recommended) and maintains consistent performance in the presence of metal ions, with no adverse effects on shade development. Available in dark red powder form, it offers excellent water solubility (50 g/L at 90°C) and builds uniformly to achieve deep, saturated shades.
For leather finishing, Acid Red 249 provides deep penetration and brilliant coloration on finished leathers and wet-blue stocks. Its application extends to paper dyeing, ink manufacturing, and the production of lake pigments, demonstrating true multi-industry versatility.
2.Product Specifications (Technical Data Sheet)
| Property | Specification | Insight |
| Product Name | Acid Red 249 (Weak Acid Brilliant Red B / Tracid Brilliant Red B) | Premium milling acid dye for high-performance applications. |
| Appearance | Dark Red to Reddish-Brown Uniform Powder | Free-flowing, micronized formulation. |
| CAS No. | 6416-66-6 | Verified chemical registry number. |
| EINECS/EC No. | 229-129-2 | Listed in European inventory. |
| Solubility | Water (25°C): ≥15 g/L; Water (90°C): ≥50 g/L; Ethanol: <10 g/L; DMSO: Soluble | Excellent hot water solubility; suitable for high-temperature dyeing. |
| Solubility in DMSO | Soluble (for research applications) | Enables formulation for specialized studies. |
| Style | Anionic / Weak Acid Dye (Milling Type) | Suitable for application in weakly acidic baths. |
| pH Value (1% solution) | 8.50 - 10.50 | Slightly alkaline in solution. |
| Tinting Strength | High (Absorbance E at 523 nm) | Strong coloration with minimal dosage. |
| λmax | 523 nm (in water) | Characteristic bluish-red absorption peak for quality verification. |
| Purity (Dye Content) | Technical Grade: ≥95-98% / Research Grade: ≥98% (HPLC) | High purity grades available. |
| Water Content | ≤ 8% | Low moisture content ensures stability. |
| Water Insolubles | ≤ 0.2% | High purity with minimal residue. |
| Fineness (80 mesh) | ≤ 8% | Consistent particle size for uniform dissolution. |
| Lightfastness (Nylon 1%) | 4 (ISO) | Good lightfastness for apparel applications. |
| Wash Fastness (50°C) | Nylon: 5; Wool: 4 | Excellent wash fastness. |
| Perspiration Fastness | Nylon: 4; Wool: 3-4 | Good resistance to perspiration. |
| Rubbing Fastness (Wet/Dry) | Dry: 4-5; Wet: 4-5 | Excellent rub fastness. |
| Packing | 25 kg HDPE bags / 500 kg jumbo bags / 10g-1kg research packs | Secure, moisture-proof packaging options available. |
| Melting Point | >300°C (Decomposes) | High thermal stability for industrial processing. |
| Storage Conditions | Store in cool, dry, dark place; avoid moisture. Research grade: Powder -20°C (3 years) / 4°C (2 years). | Extended shelf life under proper storage. |
| Application | Wool, Silk, Nylon, Leather, Paper, Inks, Lake Pigments, Cleaners | Versatile across multiple industries |
3.Product Application (Industry Usage Guide)
Textile Industry (Wool, Silk & Nylon/Polyamide):
Acid Red 249 is specifically designed for exhaust dyeing, direct printing, and continuous processing of protein and polyamide fibers. Apply at a pH of 4.5-5.5 using acetic acid for optimal exhaustion. Its milling-type character provides:
Wool Dyeing: Excellent penetration and leveling with good fastness to washing and perspiration; suitable for dyeing wool/rayon blended fabrics in combination with direct dyes.
Nylon Dyeing: Produces brilliant bluish-red shades on nylon 6 and nylon 66 with outstanding wet fastness; recommended for swimwear, activewear, and automotive textiles.
Silk Dyeing: Delivers vibrant, clean reds with good lightfastness for luxury silk garments.
Printing Applications: Suitable for direct printing on wool and nylon fabrics with excellent definition and color yield.
Leather Finishing:
In leather applications, Acid Red 249 serves as a drum dye or spray dye for finished leathers and wet-blue stocks. It provides:
Deep penetration with brilliant bluish-red coloration
Excellent coverage of grain surfaces without plating
Good lightfastness for finished leather goods
Suitable for aniline and semi-aniline leather finishing
Paper & Printing Industries:
The dye is widely used in:
Paper Pulp Coloring: Provides uniform red shades for specialty papers and packaging materials
Ink Manufacturing: Used in water-based inks, stationery products, and printing applications
Lake Pigment Production: Intermediate for manufacturing red lake pigments for paints and coatings.
Household & Industrial Cleaners:
Acid Red 249 is recommended for coloration of:
Dishwashing Detergents: Stable in alkaline formulations
Household Cleaners: Provides aesthetic red coloration to liquid cleaning products
Industrial & Institutional Cleaners: Compatible with various cleaning chemistries
Granules: Suitable for coloring detergent granules and solid cleaning formulations
Stationery Products:
The dye finds extensive application in:
Office Supplies: Coloring of pens, markers, and stamp pads
Writing Instruments: Provides consistent flow and vibrant red color for fountain pens and roller balls
Research & Environmental Applications:
In scientific research, Acid Red 249 serves as:
Model Compound: Used in photocatalytic degradation studies for wastewater treatment
Biodegradation Research: Studying microbial decolorization and dye removal from textile effluents using organisms like Bacillus flexus.
Adsorption Studies: Evaluating removal efficiency on novel adsorbents and composites
Analytical Chemistry: Reference standard for HPLC and spectroscopic analysis.
4.Packaging
Usually is 25Kg/drum or paper box or bag with inner double PE liner Or provide customized packaging according to customer requirements.
5.Our advantage:
1) Provide free samples for testing or comparing the effect difference and cost performance.
2) Fast response speed, customers' questions at any time will be responded to in two hours.
3) Fast delivery: the fastest delivery can be made on the same day.
4)Different packaging solutions: provide various packaging options according to customer requirements.
5)Technical guidance: provide improved whitening and coloring formulas and guidance according to customer production materials.
6) Sample retention or sample mailing before bulk delivery.
7) Providing certificationes, such as Reach certification.
8) Different payment methods: TT LC, etc.
9) Providing door-to-door DDP service.