Optical Brightners

Optical Brightners

Optical brighteners have been used for many years to improve the colour of various plastics. They are able to mask inherent yellowness in discoloured polymers or impart unique, robust colour to speciality plastic products. Daniel A. Jervis of Eastman Chemical Company describes the key properties of two of the main optical brighteners available for thermoplastics and describes how they can be used cost effectively in a broad range of plastics products to enhance aesthetics and consumer appeal.

Optical brighteners  OBChemical Name:


Formula C26H26N2O2S
MW      430
CAS# 7128-64-5

Synonym Name:

Uvitex Ob, Tinopal OB, Fluorescent Brightener 184 (FB 184) , c.i.184, Fluorescent Brightener OB


Appearance Slight greenish yellow powder
Dosage 0.01-0.05%
Melting point 196-200℃
Purity ≥99%
Solubility (g/100 g solution) at 20° C:
Acetone 0.5
Chloroform 14
Dimethylformamide 0.8
Dioxane 2
n-Hexane 0.2
Methanol <0.1
Methylethylketone 1.3
Tricresylphosphate 0.8
Xylene 5


>Features:Brilliant bluish whitening effects; excellent heat resistance; high chemical stability; good compatibility in a wide range of resin.

>Optical Brightener OB is used as an brightener and to offset the yellowness of a polymer and yield a whiter appearance. Mainly used as thermoplastic (PVC, PS, PE, PP, ABS) optical brightener. Also for coatings, printing inks, paints, dyes, manufactured fibers, synthetic leather, waxes, fats, and oils. Recommend indoor use only.

>If OB must be used in combination with a UV absorber, the absorption spectrum of the latter must leave an open window in the near UVA for the optical brightener ob.

>Recommended concentrations:0.02-5% depend on the application and degree of desired whiteness.

Handing and Safety: 

>FDA approved for use in polymers subject to the limitations in 21 CFR §176.170(c).

>For additional handing and toxicological information, please consult us for Maternal Safety Date Sheet.


25kg per fiber drum, 6*2 layer 12 drum per pallet, 5CBM per ton,or according to customers’ requirements.


Optical brighteners  OB1Chemical Name:


Formula C28H18N2O2
MW      414
CAS# 1533-45-5

Synonym name:

Fluorescent Brightener 393 (FB 393 ) , C.I.393,  Fluorescent Brightener OB-1, Eastobrite OB-1


Appearance yellowish or greenish


Melting point 357-359℃
Solubility (g/100 g solution) at 20° C:
Acetone <0.1
Chloroform <0.1
Hexane <0.1
Methanol <0.1
Water <0.1


>FeaturesBrilliant, neutral white cast that compensates for yellowing; Low volatility and excellent heat resistant make the product ideal for use in fibers and in engineering plastics processed at high temperatures; Good light fastness;

>OB-1 is excellent oxazole type brightener, Mainly used in whitening of polyester and ABS, PS, HIPS, PA, PC, PP, EVA, rigid PVC etc., also used as nylon fluorescent brightener.

>Recommended concentrations:0.005-0.2% depend on the application and degree of desired whiteness.


25kg per fiber drum with PE liner