Description

C.I. Direct Red 221 is a high-performance, water-soluble disazo direct dye known for its strong affinity to cellulosic fibers. It is valued in industrial applications for its excellent build-up properties, good lightfastness, and ability to produce deep, vibrant shades. This dye is primarily used by manufacturers in the textile, paper, and leather industries for dyeing and printing processes where consistent color yield and fastness are critical.

Application

• Textile Dyeing: Primary application for dyeing cotton, viscose, rayon, and other cellulosic fibers to achieve red shades.
• Paper Coloring: Used in the production of colored paper, tissues, and paperboard where water-fastness is required.
• Leather Finishing: Employed in dyeing leather goods, providing uniform coloration with good penetration.
• Ink Formulation: A component in the manufacture of inks for specific printing applications.
• Biological Staining: Potential use as a histological stain in laboratory settings.

Basic Information

Product Name	C.I. Direct Red 221
CAS No.	12222-46-7
Molecular Formula	C35H25N7Na2O10S2
Molecular Weight	837.72 g/mol
Synonyms	Direct Red 221; C.I. 29160; Direct Fast Scarlet 4BS; Pontamine Scarlet 4BS; Sirius Scarlet 4BS; Direct Scarlet 4BS; Benzo Scarlet 4BS; Atul Direct Scarlet 4BS; Solius Scarlet 4B; Dinamine Scarlet 4BS
EINECS	Contact for details

Quality Control

Our C.I. Direct Red 221 is manufactured under a stringent quality management system. Each batch is tested to ensure consistent strength, shade, and application performance. Key parameters such as dye content, solubility, and fastness properties are verified. A Certificate of Analysis (COA) detailing purity and specification conformance is provided with every shipment.

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 hygroscopic (moisture-sensitive); ensure the container is sealed after each use to prevent moisture absorption and caking.

Specification

Item	Specification
Appearance	Reddish-brown powder
Identification (IR)	Conforms to standard
Dye Content	≥ 95% (Typical)
Moisture Content	≤ 5.0%
Water Insoluble Matter	≤ 1.0%
Shade	Conforms to standard
Solubility in Water	Conforms
Fastness Properties (Light, Wash)	Standard Grade

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