Description

Fluorescent Brightener 28 is a high-performance stilbene derivative optical brightening agent (OBA) widely used to enhance the whiteness and brightness of various materials. Its core value lies in its ability to absorb ultraviolet light and re-emit it as visible blue light, effectively counteracting yellowing and creating a visually brighter, cleaner appearance. This product is essential for manufacturers in the plastics, synthetic fibers, coatings, and detergent industries seeking to improve the aesthetic quality and market appeal of their finished products.

Application

• Plastics and Polymers: Used as an additive in PVC, polyolefins (PP, PE), ABS, and engineering plastics to achieve brilliant whiteness and mask inherent yellowness.
• Synthetic Fibers: Applied in the spin finish or during the polymerization process for polyester, nylon, and acrylic fibers to produce exceptionally white textiles.
• Detergents and Laundry Care: A key component in laundry detergents, fabric softeners, and soaps to impart a "whiter-than-white" effect on fabrics.
• Coatings and Paints: Incorporated into industrial and decorative coatings to improve brightness and opacity.
• Paper and Pulp: Used in high-quality paper manufacturing, including photographic paper and art paper, to achieve high brightness grades.
• Printing Inks: Enhances the visual impact and brightness of printed materials.

Basic Information

Product Name	Fluorescent Brightener 28
CAS No.	4404-43-7
Molecular Formula	C₄₀H₄₂N₁₂O₆S₂
Molecular Weight	843.0 g/mol
Synonyms	2,2'-(1,2-Ethenediyldi-4,1-phenylene)bisbenzoxazole; 4,4'-Bis(2-benzoxazolyl)stilbene; OB-1; Fluorescent Brightener OB-1; Tinopal OB; Blankophor ER; Hakkol PSN; Eastobrite OB-1
EINECS	224-548-1

Quality Control

Our Fluorescent Brightener 28 is manufactured under a strict quality management system. Every batch undergoes comprehensive analytical testing to ensure consistent performance, including purity assay, absorption/emission spectrum verification, and physical property checks. A Certificate of Analysis (COA) detailing the specific results is provided with each shipment to guarantee it meets your application requirements and our high industry standards.

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). Keep away from heat sources and incompatible materials. Due to its light-sensitive nature, prolonged exposure to direct light should be avoided to maintain product efficacy.

Specification

Item	Specification
Appearance	Light yellow to yellow-green crystalline powder
Identification (IR)	Conforms to standard
Purity (HPLC)	≥ 99.0%
Melting Point	358 - 362 °C
Loss on Drying	≤ 0.5%
Ash Content	≤ 0.2%
Fluorescence Intensity	≥ 100% (vs. Standard)

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