Description

Tetrasodium 4,4'-Bis[[2,5-Dimethyl-4-[(4-Sulphonatophenyl)Azo]Phenyl]Azo]Stilbene-2,2'-Disulphonate is a high-purity, water-soluble fluorescent whitening agent (FWA) belonging to the stilbene derivative class. This compound is valued for its exceptional ability to absorb ultraviolet light and re-emit it as visible blue light, thereby enhancing the perceived whiteness and brightness of treated materials. It is a critical additive for manufacturers in the textile, paper, detergent, and plastics industries seeking to achieve superior optical brightening effects in their products.

Application

• Textile Finishing: Primary application for whitening and brightening cotton, nylon, wool, and synthetic fibers during scouring, bleaching, or finishing processes.
• Paper Manufacturing: Used in coating formulations and pulp to improve the optical brightness and quality of high-grade printing, writing, and tissue papers.
• Laundry Detergents & Fabric Softeners: A key ingredient in household and industrial detergents to impart a "whiter-than-white" appearance to laundered fabrics.
• Plastics and Polymers: Incorporated into polymers like PVC, polyolefins, and styrenics to counteract yellowing and enhance the brightness of molded or extruded articles.
• Soaps and Personal Care: Employed in certain cosmetic and soap formulations to improve visual appeal.
• Synthetic Fiber Production: Applied during the spinning process of man-made fibers to achieve inherent brightness.

Basic Information

Product Name	Tetrasodium 4,4'-Bis[[2,5-Dimethyl-4-[(4-Sulphonatophenyl)Azo]Phenyl]Azo]Stilbene-2,2'-Disulphonate
CAS No.	85959-56-4
Molecular Formula	C~46~H~34~N~8~Na~4~O~14~S~4
Molecular Weight	1153.0 g/mol (approx.)
Synonyms	Fluorescent Brightener 220; Tinopal CBS-X; Blankophor BBU; 4,4'-Bis(2-sulfostyryl)biphenyl tetrasodium salt derivative; Stilbene-based optical brightener; FWA 220; 2,2'-(1,2-Ethenediyl)bis[5-[[4-[(4-sulfophenyl)azo]-2,5-dimethylphenyl]azo]benzenesulfonic acid] tetrasodium salt; CI Fluorescent Brightener 220
EINECS	Contact for details

Quality Control

Our production of Tetrasodium 4,4'-Bis[[2,5-Dimethyl-4-[(4-Sulphonatophenyl)Azo]Phenyl]Azo]Stilbene-2,2'-Disulphonate adheres to stringent quality management protocols to ensure batch-to-batch consistency and performance reliability. Each lot is analyzed for critical parameters including purity, shade, and solubility. A comprehensive Certificate of Analysis (COA) detailing assay (HPLC), absorbance characteristics, moisture content, and heavy metal limits is provided with every shipment to support your quality assurance and regulatory compliance needs.

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); the container must be kept tightly sealed after opening to prevent absorption of atmospheric moisture, which can affect performance and flow characteristics.

Specification

Item	Specification
Appearance	Yellowish to light brown powder
Identification (IR)	Conforms to standard
Assay (HPLC)	≥ 95.0%
Moisture Content	≤ 5.0%
pH (1% Solution)	7.0 - 10.0
Water Solubility	Freely soluble
Heavy Metals (as Pb)	≤ 20 ppm
Ash Content (Sulfated)	Contact for details

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