Description

Tetrapotassium 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonate is a high-purity, water-soluble anionic dye belonging to the stilbene azo class. This compound matters for its exceptional optical properties, serving as a critical functional additive and colorant in advanced industrial applications. It is primarily needed by manufacturers in the paper, textile, and specialty polymer industries seeking to enhance product brightness and optical performance.

Application

• Optical Brightening Agent (OBA) or Fluorescent Whitening Agent (FWA) for high-quality papers and boards.
• Textile Brightener for synthetic fibers like polyamide and polyester to improve whiteness and brightness.
• Polymer Additive for engineering plastics and coatings to impart fluorescence and visual appeal.
• Detergent Formulation component in premium laundry products for fabric whitening effects.
• Analytical Chemistry as a fluorescent probe or tracer in specific biochemical and environmental assays.
• Security Ink Formulation for anti-counterfeiting applications due to its distinctive fluorescent properties.

Basic Information

Product Name	Tetrapotassium 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonate
CAS No.	94134-52-8
Molecular Formula	C32H20K4N4O10S2
Molecular Weight	826.14 g/mol
Synonyms	4,4'-Bis[(4-hydroxyphenyl)azo]stilbene-2,2'-disulfonic acid tetrapotassium salt; Tetrapotassium 4,4'-diaminostilbene-2,2'-disulfonate azo dye; Fluorescent Brightener KSN; Paper Brightener 220; FWA 220; Stilbene Brightener K; CI Fluorescent Brightener 220 (Potassium Salt)
EINECS	Contact for details

Quality Control

Our Tetrapotassium 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 consistent purity, color strength, and performance. A comprehensive Certificate of Analysis (COA) detailing assay, impurity profile, and physical specifications is provided with each shipment to guarantee compliance with your application 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). Due to its hygroscopic (moisture-sensitive) nature, the container must be kept sealed when not in use to prevent absorption of atmospheric moisture.

Specification

Item	Specification
Appearance	Yellow to orange-yellow powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Color Strength	98 - 102% (vs. Standard)
Moisture (KF Titration)	≤ 5.0%
Ash Content	≤ 20.0%
pH (1% Aqueous Solution)	7.0 - 9.0
Solubility in Water	Clear, yellow solution

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