Description

Direct Fast Red 3B is a synthetic azo dye belonging to the class of direct dyes, valued for its bright red hue and strong affinity for cellulosic fibers. Its primary commercial value lies in its ability to provide vibrant, wash-fast coloration to textiles without the need for a mordanting step, streamlining the dyeing process. This product is essential for manufacturers in the textile industry, particularly for dyeing cotton, viscose, and paper, where consistent color strength and batch-to-batch reliability are critical.

Application

• Primary dyeing of cotton fabrics and yarns for apparel and home textiles.
• Coloration of viscose (rayon) and other regenerated cellulose fibers.
• Dyeing of paper and paperboard for decorative and packaging applications.
• Used in the production of leather for coloring finished goods.
• Potential use as a biological stain in laboratory and microscopy settings.
• Coloration of silk and wool, often in combination with other dyes.

Basic Information

Product Name	Direct Fast Red 3B
CAS No.	6358-29-8
Molecular Formula	C32H21N7Na2O10S2
Molecular Weight	781.66 g/mol
Synonyms	Direct Red 23; C.I. 29160; Direct Fast Scarlet 4BS; Pontamine Fast Red 3B; Sirius Red 3B; Direct Red 3B; Direct Fast Red 3B; Benzo Fast Red 3BL
EINECS	228-782-5

Quality Control

Our Direct Fast Red 3B is manufactured under a strict quality management system. Every batch is tested to ensure it meets high-purity standards and consistent dyeing performance. Key parameters such as color strength, shade, solubility, and impurity profiles are rigorously verified. A Certificate of Analysis (COA) detailing all test results is provided with each shipment to guarantee traceability and compliance with your specifications.

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 heat, sparks, and open flame. Due to its light-sensitive nature, prolonged exposure to direct light should be avoided to prevent degradation of the dye.

Specification

Item	Specification
Appearance	Reddish-brown powder
Identification (IR)	Conforms to standard
Assay (Dye Content)	Min. 95%
Moisture Content	Max. 5.0%
Water Insoluble Matter	Max. 0.5%
Shade	Conforms to standard sample
Solubility in Water	Conforms
pH (1% Solution)	7.0 - 9.0

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