Description

Direct Black 56 is a synthetic, high-strength direct dye belonging to the benzidine-derived azo dye class, widely recognized for its deep, neutral black shade and excellent build-up properties. Its primary value lies in providing a cost-effective and reliable coloring solution for cellulosic fibers with good wash fastness. This dye is essential for manufacturers in the textile industry, particularly for dyeing and printing cotton, viscose, rayon, and paper, where a deep black color is required.

Application

• Primary dyeing of cotton and viscose/rayon fabrics and yarns.
• Printing applications on cellulosic textiles to achieve deep black patterns.
• Coloration of paper and paperboard products.
• Dyeing of leather to impart a uniform black color.
• Tinting of wood and related materials.
• Used in the formulation of inks for specific applications.

Basic Information

Product Name	Direct Black 56
CAS No.	8003-57-4
Molecular Formula	C34H25N9Na4O13S4
Molecular Weight	1083.88 g/mol
Synonyms	Direct Black 56; Direct Black BN; C.I. Direct Black 56; Direct Deep Black EW; Direct Black G; Pontamine Black EBN; Aizen Direct Deep Black BH; Atul Direct Black BN; Benzo Deep Black E; Sirius Black B
EINECS	232-325-6

Quality Control

Our production of Direct Black 56 adheres to stringent quality management protocols to ensure batch-to-batch consistency and performance reliability. Each lot is tested against key parameters including color strength, shade, solubility, and fastness properties. Certificates of Analysis (COA) detailing these specifications are available upon request to support your quality assurance processes.

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 and incompatible materials.

Specification

Item	Specification
Appearance	Black to Bluish-Black Powder
Identification (IR)	Conforms to Standard
Color Strength	100 ± 3% (vs. Standard)
Shade	Conforms to Standard
Moisture Content	≤ 5.0%
Water Insoluble Matter	≤ 1.0%
Solubility in Water	Conforms
Fastness Properties	Typical values available on TDS

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