Description

Tetrasodium 4,4'-Bis[[p-[(p-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 engineered to provide exceptional optical brightening effects by absorbing ultraviolet light and re-emitting it as visible blue light, thereby enhancing the perceived whiteness and brightness of materials. It is a critical additive for manufacturers in the detergent, paper, textile, and plastics industries seeking to improve product aesthetics and meet stringent quality standards.

Application

• Detergent & Laundry Care: Primary application as an optical brightener in laundry detergents, powders, and liquids to make white fabrics appear brighter and colored fabrics more vivid.
• Paper Manufacturing: Used in the production of high-quality writing, printing, and tissue papers to achieve a superior bright white finish.
• Textile & Fiber Treatment: Applied in the finishing process of natural and synthetic fibers, yarns, and fabrics to enhance whiteness, especially for cotton, nylon, and polyester.
• Plastics & Polymers: Incorporated into polymers, synthetic fibers, and plastic products to correct yellowness and improve initial color.
• Coatings & Paints: Utilized in specific coating formulations where optical brightening is required for a clean, bright appearance.
• Soap & Personal Care: Added to certain soaps and personal care products to provide a visual signal of cleanliness and purity.

Basic Information

Product Name	Tetrasodium 4,4'-Bis[[p-[(p-Sulphonatophenyl)Azo]Phenyl]Azo]Stilbene-2,2'-Disulphonate
CAS No.	32829-81-5
Molecular Formula	C40H24N8Na4O14S4
Molecular Weight	1065.0 g/mol (approx.)
Synonyms	Fluorescent Brightener 71; Tinopal CBS-X; FWA 71; Stilbene-based optical brightener; 4,4'-Bis(2-sulfostyryl)biphenyl tetrasodium salt (related core structure); Tetrasodium 4,4'-bis(2-sulfonatostyryl)biphenyl-2,2'-disulfonate; Optical Brightening Agent OBA-71; CI Fluorescent Brightener 71.
EINECS	251-248-8

Quality Control

Our production of Tetrasodium 4,4'-Bis[[p-[(p-Sulphonatophenyl)Azo]Phenyl]Azo]Stilbene-2,2'-Disulphonate adheres to stringent quality management protocols. Every batch undergoes comprehensive analytical testing, including HPLC for purity and spectrophotometry for strength and shade, to ensure consistent performance and compliance with industry specifications. A detailed Certificate of Analysis (COA) documenting purity, physical properties, and performance characteristics is provided with each shipment.

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). Due to its hygroscopic (moisture-sensitive) nature, 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 structure
Assay (HPLC)	≥ 95.0%
Moisture Content	≤ 5.0%
pH (1% Solution)	7.0 - 9.0
Fluorescent Strength	98 - 102% (vs. Standard)
Ash Content (Sulfated)	≤ 20.0%
Solubility in Water	Clear, yellow solution

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