Description

Dilithium Disodium 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonate CAS NO 66104-72-1 is a high-purity, water-soluble, anionic dye belonging to the stilbene class, characterized by its distinct azo and sulfonate functional groups. This compound is valued for its strong and stable color properties, making it a critical component in specialized industrial applications where consistent performance is required. It is primarily utilized by manufacturers in the textile, paper, and specialty chemical sectors for its functional dyeing and optical brightening capabilities.

Application

• Textile Dyeing and Printing: Used as a direct dye for cotton, viscose, and other cellulosic fibers, providing bright and wash-fast shades.
• Paper Coloring: Employed in the surface coloring and coating of high-quality papers and specialty boards.
• Optical Brightening Agent (OBA): Functions as a fluorescent whitening agent in detergents, plastics, and coatings to enhance visual brightness.
• Liquid Crystal Display (LCD) Manufacturing: Serves as a dichroic dye guest in guest-host LCDs for specific optical filter applications.
• Ink Formulation: Incorporated into inks for security printing, packaging, and specialty marking where color stability is paramount.
• Biological Staining: Used in research and diagnostic applications as a histological stain due to its selective binding properties.
• Polymer Additive: Acts as a colorant and UV-stabilizing additive in certain engineering plastics and synthetic fibers.

Basic Information

Product Name	Dilithium Disodium 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonate
CAS No.	66104-72-1
Molecular Formula	C32H20Li2N4Na2O10S2
Molecular Weight	744.56 g/mol
Synonyms	4,4'-Bis[(4-hydroxyphenyl)azo]stilbene-2,2'-disulfonic acid, dilithium disodium salt; Stilbene disulfonic acid azo dye; Direct Yellow 11 (related class); C.I. 40000; Fluorescent Brightener 220; Tinopal CBS (trade name analogue); Bisazo stilbene dye; 4,4'-Diaminostilbene-2,2'-disulfonic acid azo dye derivative
EINECS	266-200-8

Quality Control

Our production of Dilithium Disodium 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonate adheres to stringent quality management protocols to ensure batch-to-batch consistency and purity. Each lot is analyzed against comprehensive specifications using advanced techniques like HPLC and spectrophotometry. A Certificate of Analysis (COA) detailing identity, purity, and impurity profiles is provided with every shipment, supporting compliance with global regulatory and customer-specific requirements.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at a controlled room temperature (15-25°C). Keep away from heat sources and incompatible materials. Due to its light-sensitive nature, prolonged exposure to direct light should be avoided to maintain product integrity.

Specification

Item	Specification
Appearance	Orange to reddish-brown powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Loss on Drying	≤ 5.0%
Sulfated Ash	≤ 20.0%
Heavy Metals (as Pb)	≤ 20 ppm
Water Solubility	Freely soluble
λmax (in water)	430 - 450 nm

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