Optical Brightener OB

Optical brighteners has the function of improving the whiteness in both plastics and textile fibers. In nylon fibers and polyester, optical brightener gives a pleasing white appearance. With its good thermal stability, excellent brightening ability, and compatibility with many polymers, It is effective in the brightening of many plastics. Optical Brightener OB provides an outstanding white and permanent color as it can be dissolved in the polymer or fiber during polymer production. This permanence gives much better brightness retention by comparing with methods like surface treatment with optical brighteners or bleaching. They can absorb ultraviolet radiation and re-emit blue light. The emitted blue light can reduce the yellow color of the polymer.

Product Details

Chemical information 

Color Index No:C.I.184

Synonyms:FBA 184; 2,5-Bis-/5-tert.-butyl-2-benzoxazolyl)-thiophene;2,5-Thiophenediylbis(5-tert-butyl-1,3-benzoxazole);2,2′-thiene-2,5-diylbis(5-tert-butyl-1,3-benzoxazole);Fluorescent Brightener OB;

Molecular Structure:

OB molecular

Molecular Formula:C26H26N2O2S Molecular Weight:430.5618
CAS No:7128-64-5 EINECS No: 230-426-4
Density(g/cm3):/ Average particle size(um):Pass 300 mesh
Specific surface(m2/g):/ Oil Absorption(g/100g):/
Melting point(℃):201-202 Assay:99%


It can help colors become more brilliant and get outstanding brightening ability. Adding OB can produce a bluish tinge and mask yellowness, as well as create whiter look than normal white apperance. It is an enviromental friendly brightener.


Solvent based ink; Solvent based paint,coatings; Polyester, man-made fibers,polymers,recycled polymers;