Description

Mordant Brown 33 is a synthetic organic dye belonging to the mordant dye class, identified by CAS NO 3618-62-0. This compound is valued for its ability to form stable, colorfast complexes with metal ions, primarily chromium, resulting in durable brown shades on various substrates. It is an essential industrial colorant for manufacturers in the textile, leather, and specialty paper industries seeking consistent and wash-fast coloration.

Application

• Textile Dyeing: Primarily used for dyeing wool, silk, and nylon fibers, where it forms stable complexes with chrome mordants to produce brown hues with excellent light and wash fastness.
• Leather Finishing: Applied in the coloring of leather goods, providing rich, uniform brown tones that penetrate deeply and resist fading.
• Paper Staining: Employed in the production of specialty papers, including decorative and packaging materials, requiring specific color shades.
• Wood Staining: Used as a colorant in wood stains and finishes to achieve desired brown shades on timber and wood products.
• Biological Staining (Histology): May be utilized in laboratory settings as a histological stain for microscopic tissue analysis.
• Ink Formulation: Serves as a pigment component in the manufacture of certain industrial inks.

Basic Information

Product Name	Mordant Brown 33
CAS No.	3618-62-0
Molecular Formula	C20H12N3NaO8S
Molecular Weight	477.38 g/mol
Synonyms	Acid Chrome Brown K; C.I. Mordant Brown 33; Chrome Brown K; C.I. 13250; Mordant Brown K; Acid Brown 45; 4,4'-[(2-Hydroxy-5-sulfo-1,3-phenylene)bis(azo)]bis[5-methyl-2-phenyl-3H-pyrazol-3-one] disodium salt
EINECS	222-826-7

Quality Control

Our Mordant Brown 33 is manufactured under a stringent quality management system to ensure batch-to-batch consistency and performance. Each lot is tested against key parameters including color strength, shade, solubility, and impurity profile. Certificates of Analysis (COA) documenting purity, heavy metal content, and other relevant specifications are available upon request to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Keep away from strong oxidizing agents. The product is light-sensitive (store away from light).

Specification

Item	Specification
Appearance	Brown powder
Identification (IR)	Conforms to standard
Assay (Dye Content)	Min. 95%
Moisture Content	Max. 5.0%
Water Solubility	Conforms
Ash Content	Max. 1.0%
Heavy Metals (as Pb)	Max. 20 ppm
Shade	Standard match

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