Description

Tetrasodium 4,4'-Bis[[2-Methoxy-5-Methyl-4-[(4-Sulphonatophenyl)Azo]Phenyl]Azoxy]Stilbene-2,2'-Disulphonate is a high-performance, water-soluble fluorescent whitening agent (FWA) belonging to the stilbene derivative class. It is engineered to deliver exceptional optical brightening effects by absorbing ultraviolet light and re-emitting it as visible blue light, thereby enhancing the perceived whiteness and brightness of substrates. This product is essential for manufacturers in the textile, paper, detergent, and plastics industries seeking to improve the aesthetic appeal and market value of their finished products.

Application

• Textile Finishing: Primary application for whitening and brightening cotton, nylon, polyester, and blended fabrics during scouring, bleaching, or finishing processes.
• Paper Manufacturing: Used in coating formulations and pulp to achieve high-brightness, blue-white shades in premium writing, printing, and tissue papers.
• Detergent & Laundry Care: A key additive in laundry detergents, fabric softeners, and soaps to compensate for yellowing and maintain fabric whiteness over multiple washes.
• Plastics and Polymers: Incorporated into synthetic fibers, films, and molded plastic articles to correct inherent yellowness and improve visual quality.
• Cosmetics and Personal Care: Employed in formulations where a bright, clean visual impression is desired, subject to regional regulatory compliance.
• Advanced Material Coatings: Used in specialty paints, coatings, and inks to provide optical brightening effects under UV light.

Basic Information

Product Name	Tetrasodium 4,4'-Bis[[2-Methoxy-5-Methyl-4-[(4-Sulphonatophenyl)Azo]Phenyl]Azoxy]Stilbene-2,2'-Disulphonate
CAS No.	70304-37-9
Molecular Formula	C46H36N8Na4O18S4
Molecular Weight	~1197.0 g/mol
Synonyms	Fluorescent Brightener 220; FWA 220; Tinopal CBS-X; Stilbene-based Optical Brightener 220; 4,4'-Bis[[2-Methoxy-5-Methyl-4-[(4-Sulfonatophenyl)Azo]Phenyl]Azoxy]Stilbene-2,2'-Disulfonic Acid Tetrasodium Salt; CBS-X; Distyrylbiphenyl Derivative; Optical Brightening Agent OBA 220
EINECS	Contact for details

Quality Control

Our production of Tetrasodium 4,4'-Bis[[2-Methoxy-5-Methyl-4-[(4-Sulphonatophenyl)Azo]Phenyl]Azoxy]Stilbene-2,2'-Disulphonate adheres to stringent quality management systems. Every batch undergoes rigorous testing to ensure consistent performance in strength, hue, and solubility. Key parameters such as purity, ash content, and heavy metals are monitored. A Certificate of Analysis (COA) detailing specific batch results is provided with each shipment to guarantee compliance with your technical requirements.

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). This product is hygroscopic (moisture-sensitive); therefore, the container must be kept tightly sealed after opening to prevent moisture absorption and caking. Keep away from incompatible materials.

Specification

Item	Specification
Appearance	Yellowish to light brown powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 95.0%
Moisture Content	≤ 5.0%
Ash Content (Sulfated)	≤ 20.0%
pH (1% Solution)	7.0 - 9.0
Water Solubility	Clear, yellow solution
Heavy Metals (as Pb)	≤ 20 ppm

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