Description

Direct Black 155 is a high-performance, diazo direct dye widely used for its excellent substantivity and deep, rich black shades. This product is valued for its reliable color yield and good fastness properties on cellulosic fibers like cotton, viscose, and paper. It is a critical component for textile mills, paper manufacturers, and leather tanneries seeking efficient and cost-effective dyeing solutions for a variety of applications.

Application

• Primary dyeing of cotton and other cellulosic textiles for apparel and home furnishings.
• Coloration of viscose rayon and blended fabrics to achieve deep black hues.
• Dyeing of paper and paperboard for packaging, decorative, and specialty paper products.
• Application in leather finishing for shoes, bags, and upholstery.
• Used in the production of inks for specific printing applications.
• Employed in laboratory settings for biological staining and as a colorimetric indicator.

Basic Information

Product Name	Direct Black 155
CAS No.	71902-06-2
Molecular Formula	C34H25N9Na4O13S4
Molecular Weight	1023.86 g/mol
Synonyms	Direct Black 155; C.I. Direct Black 155; Direct Black EX; Direct Black G; Direct Deep Black EW; Pontamine Black E; Atul Direct Black D; Benzo Deep Black E; Sirius Black SB; Diazol Black 2B; Direct Black (C.I. 30235)
EINECS	Contact for details

Quality Control

Our Direct Black 155 is manufactured under strict quality management systems to ensure batch-to-batch consistency and performance reliability. Every lot is tested against stringent internal specifications for key parameters such as color strength, shade, solubility, and impurity profile. A Certificate of Analysis (COA) detailing these results is provided with each shipment to guarantee compliance with your technical requirements.

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). This material is hygroscopic (moisture-sensitive); keep the container tightly sealed when not in use to prevent absorption of atmospheric moisture, which can affect performance.

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
pH (1% Solution)	6.0 - 8.0

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