Description

C.I. Acid Brown 321 is a synthetic azo dye belonging to the acid dye class, characterized by its brown hue and good affinity for protein-based fibers. This dye is valued for its ability to produce consistent, level shades with good wash and light fastness properties on various substrates. It is primarily utilized in the textile and leather industries for dyeing wool, silk, nylon, and other polyamide materials, as well as in the coloration of paper and specialty inks.

Application

• Dyeing of wool and silk fabrics and yarns.
• Coloration of nylon and other synthetic polyamide fibers.
• Leather dyeing for footwear, apparel, and upholstery.
• Paper coloring for specialty packaging and decorative papers.
• Ink formulation for stamp pads and specialty printing.
• Biological staining applications in microscopy (specific grades).

Basic Information

Product Name	C.I. Acid Brown 321
CAS No.	61931-10-0
Molecular Formula	C32H24N8Na4O16S4
Molecular Weight	1048.88 g/mol
Synonyms	Acid Brown 321; Acid Leather Brown 2GL; C.I. 20185; Acid Fast Brown GL; Nylosan Brown E-RL; Telon Brown K-3GL; Acid Brown GL; Leather Brown A-GL
EINECS	Contact for details

Quality Control

Our C.I. Acid Brown 321 is manufactured under a strict quality management system. Each batch undergoes comprehensive testing to ensure it meets consistent standards for color strength, shade, solubility, and fastness properties. Certificates of Analysis (COA) detailing purity, heavy metal content, and other critical parameters are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Keep away from incompatible materials. The product is light-sensitive and should be stored away from direct light exposure.

Specification

Item	Specification
Appearance	Brown powder or granules
Identification (IR)	Conforms to standard
Color Strength	100 ± 3% (vs. Standard)
Moisture Content	≤ 5.0%
Water Insoluble Matter	≤ 1.0%
pH (1% Solution)	6.0 - 8.0
Heavy Metals (as Pb)	≤ 50 ppm
Fastness Properties	To be specified per grade

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.