Description

4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonic Acid, Sodium Salt is a high-purity, water-soluble azo dye intermediate and optical brightening agent. This compound is valued for its ability to impart fluorescence and color, making it a critical component in the production of advanced materials. It is primarily utilized by manufacturers in the textile, paper, detergent, and specialty polymer industries seeking to enhance product whiteness and brightness.

Application

• Optical Brightening Agent (OBA) for paper and pulp to achieve high whiteness grades.
• Fluorescent Whitening Agent (FWA) in laundry detergents and fabric softeners.
• Textile Auxiliary for synthetic fibers like polyester and nylon to improve visual appeal.
• Polymer Additive to enhance the brightness and color of plastics and coatings.
• Analytical Chemistry Reagent used as a fluorescent probe or stain in specific methodologies.
• Specialty Dye Intermediate for synthesizing more complex azo dyes and pigments.

Basic Information

Product Name	4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonic Acid, Sodium Salt
CAS No.	68966-53-0
Molecular Formula	C26H18N4Na2O8S2
Molecular Weight	632.55 g/mol
Synonyms	4,4'-Bis[(4-hydroxyphenyl)azo]stilbene-2,2'-disulfonic acid disodium salt; Sodium 4,4'-bis[(4-hydroxyphenyl)azo]stilbene-2,2'-disulfonate; Fluorescent Brightener 220; FWA 220; Paper Brightener 220; Stilbene-based optical brightener; 2,2'-(1,2-Ethenediyl)bis[5-[(4-hydroxyphenyl)azo]benzenesulfonic acid] disodium salt
EINECS	Contact for details

Quality Control

Our production of 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonic Acid, Sodium Salt adheres to stringent quality management protocols. Every batch is analyzed to ensure consistent purity, color strength, and performance as an optical brightener. A comprehensive Certificate of Analysis (COA) detailing assay, impurity profile, and physical specifications 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 material is hygroscopic (moisture-sensitive); keep the original container tightly sealed to prevent absorption of atmospheric moisture.

Specification

Item	Specification
Appearance	Yellow to orange-yellow powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Moisture Content	≤ 5.0%
Ash Content (Sulfated)	≤ 20.0%
Fluorescence Intensity	Standardized against reference
Solubility (in Water)	Clear, yellow solution

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