Description

Potassium Sodium 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonate is a high-purity, water-soluble anionic dye belonging to the stilbene class, valued for its brilliant optical properties and chemical stability. This compound is engineered to deliver consistent, high-performance coloration and fluorescence in demanding industrial applications. It is primarily utilized by manufacturers in the textile, paper, and specialty chemical industries seeking reliable and effective colorants for their processes.

Application

• Textile Dyeing and Printing: As a direct or acid dye for coloring natural and synthetic fibers, particularly where bright, light-fast shades are required.
• Paper and Pulp Industry: Used in the surface coloring of high-quality papers, board, and specialty packaging materials.
• Functional Dye Intermediate: Serves as a key precursor or additive in the synthesis of optical brighteners, fluorescent markers, and other advanced dye molecules.
• Leather Processing: Employed in the dyeing of leather goods to achieve vibrant and uniform coloration.
• Ink Formulation: A component in the manufacture of inks for various printing applications, contributing to color intensity and stability.
• Laboratory and Research: Used as a standard or reagent in analytical chemistry and materials science research due to its defined azo and sulphonate structure.

Basic Information

Product Name	Potassium Sodium 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonate
CAS No.	79069-96-8
Molecular Formula	C32H20N4O10S2•KNa (or similar salt form)
Molecular Weight	Contact for details
Synonyms	4,4'-Bis[(4-hydroxyphenyl)azo]stilbene-2,2'-disulfonic acid, dipotassium disodium salt; Direct Yellow 11 (related class); Stilbene yellow dye; Azo stilbene disulfonate; Fluorescent brightener 351 (potential application); C.I. 40000; Potassium sodium bis(azo)stilbene disulphonate; 2,2'-(1,2-Ethenediyl)bis[5-[(4-hydroxyphenyl)azo]benzenesulfonic acid] dipotassium disodium salt
EINECS	Contact for details

Quality Control

Our Potassium Sodium 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonate is produced under a stringent quality management system. Every batch undergoes rigorous analytical testing to ensure it meets precise specifications for purity, color strength, and solubility. A comprehensive Certificate of Analysis (COA) detailing assay, impurity profile, and physical parameters is provided with each shipment to guarantee consistency and support your quality assurance protocols.

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. Due to its organic dye nature, prolonged exposure to intense light or high humidity should be avoided to maintain product integrity.

Specification

Item	Specification
Appearance	Yellow to orange-brown powder
Identification (IR)	Conforms to structure
Assay (HPLC)	Min. 95%
Loss on Drying	Max. 5.0%
Sulfated Ash	Contact for details
Heavy Metals (as Pb)	Max. 20 ppm
Solubility (in Water)	Freely soluble
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.