Description

Fluorescent Brightener 121 is a high-performance stilbene-based optical brightening agent (OBA) designed to enhance the whiteness and brightness of various substrates. Its core value lies in its exceptional ability to absorb ultraviolet light and re-emit it as visible blue light, effectively counteracting yellowing and creating a brilliant, clean appearance. This product is essential for manufacturers in the plastics, synthetic fibers, and detergent industries seeking to improve the aesthetic appeal and perceived quality of their finished goods.

Application

• Primary whitening agent for a wide range of thermoplastics, including polypropylene (PP), polyethylene (PE), and polystyrene (PS).
• Brightening of synthetic fibers such as polyester, nylon, and polyacrylonitrile during spin finishing or mass pigmentation.
• Key ingredient in laundry detergents and fabric softeners for superior whitening and brightening of textiles.
• Enhancement of paper brightness in coatings and as a pulp additive for high-quality writing and printing papers.
• Used in the formulation of coatings, inks, and adhesives where optical brightness is required.
• Applicable in the production of white masterbatches for consistent and efficient dispersion in polymer processing.

Basic Information

Product Name	Fluorescent Brightener 121
CAS No.	2744-49-2
Molecular Formula	C₄₀H₄₂N₁₂O₆S₂
Molecular Weight	843.0 g/mol
Synonyms	2,2'-(1,2-Ethenediyl)bis[5-[4-[bis(2-hydroxyethyl)amino]-6-(phenylamino)-1,3,5-triazin-2-yl]amino]benzenesulfonic acid; Tinopal UNPA-GX; Blankophor P 167%; Fluorescent Brightener ER-I; OB-1; 4,4'-Bis[(4-anilino-6-bis(2-hydroxyethyl)amino-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulfonic acid; Stilbene Brightener 121
EINECS	220-378-7

Quality Control

Every batch of Fluorescent Brightener 121 is manufactured and tested under a strict quality management system. We ensure the product meets high-purity standards with consistent performance characteristics critical for industrial applications. A comprehensive Certificate of Analysis (COA), detailing parameters such as purity, hue, and strength, is provided with each shipment to guarantee supply reliability and product consistency for our global B2B clients.

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

Specification

Item	Specification
Appearance	Yellowish-green powder
Identification (IR)	Conforms
Purity (HPLC)	≥ 98.0%
Ash Content	≤ 0.5%
Moisture Content	≤ 5.0%
pH (1% aqueous dispersion)	7.0 - 9.0
Fluorescent Strength	100 ± 3% (vs. Standard)
Solubility	Soluble in water, glycols

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