Description

C.I.Direct Orange 51 is a synthetic, water-soluble direct dye belonging to the azo chemical class. It is valued for its strong and bright orange hue, offering excellent substantivity to cellulosic fibers like cotton and rayon without the need for a mordant. This dye is essential for manufacturers in the textile and paper industries seeking consistent, cost-effective coloration. Its reliable performance makes it a key component for producing dyed yarns, fabrics, and specialty papers.

Application

• Textile Dyeing: Primary application for dyeing cotton, viscose rayon, and other cellulosic fibers in exhaust and continuous dyeing processes.
• Paper Coloring: Used for tinting and surface coloring of paper, paperboard, and specialty packaging materials.
• Leather Finishing: Imparts color to leather goods, providing good penetration and levelness on tanned hides.
• Ink Formulation: A pigment source in the manufacture of inks for flexographic and other printing applications.
• Biological Staining: Potential use as a histological stain in laboratory settings for microscopic analysis.
• Craft and Educational Dyes: Suitable for use in educational kits and craft applications requiring water-based dyes.

Basic Information

Product Name	C.I. Direct Orange 51
CAS No.	61724-90-1
Molecular Formula	C32H20N6Na4O13S4
Molecular Weight	956.78 g/mol
Synonyms	Direct Orange 51; C.I. 29050; Direct Fast Orange S; Direct Orange S; Direct Orange 51 (C.I. 29050); Pontamine Orange S; Sirius Orange S; Chloramine Fast Orange S; Aizen Direct Orange S; Atlantic Direct Orange S; Benzo Orange S; Diazol Orange S; Pyrazol Orange S
EINECS	262-964-7

Quality Control

Our production of C.I. Direct Orange 51 adheres to stringent quality management protocols to ensure batch-to-batch consistency and performance reliability. Every lot is tested against key parameters including color strength, shade, solubility, and fastness properties. A comprehensive Certificate of Analysis (COA) detailing purity, physical properties, and performance metrics is provided with each shipment 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. The product is hygroscopic (moisture-sensitive); ensure containers are sealed after use to prevent moisture absorption and caking.

Specification

Item	Specification
Appearance	Orange to reddish-brown powder
Identification (IR)	Conforms to standard
Color Strength	100 ± 3% (vs. Standard)
Moisture Content	≤ 5.0%
Water Insoluble Matter	≤ 0.5%
Shade	Conforms to standard
Solubility in Water	Conforms
Fastness Properties (Typical)	Light: 4-5; Wash: 3-4; Water: 3-4

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