What is Optical brightener OB ?

Optical brightener OB(fluorescent whitening agent OB) is a kind of optical brightener called the public lover, OB shows that it has a very good fusion and is suitable for all kinds of plastics. At the same time, the optical brightener OB can also be used in paint, ink, coating, and PE film.

Optical brightener OB powder

Nickname: 2,5-Bis-/5-tert.-butyl-2-benzoxazolyl)-thiophene; Fluorescent Brightener OB; FLUOESCENT BRIGHTENER-OB; FBA 184; 2,5-Thiophenediylbis(5-tert-butyl-1,3-benzoxazole); Optical Brightener OB; 2,2'-thiene-2,5-diylbis(5-tert-butyl-1,3-benzoxazole)

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Product Cate:Optical Brightening Agent For Plastic

Product Name:Optical Brightener OB

Chemical Name:2,5'-Bis[2-(5-tert-buty l-2 benzoxazoly)thiophene

CAS No.:7128-64-5

C.I. No.:184

Molecular Formula:C26H26N2O2N2

Molecular Weight:430

Appearance:slight greenish yellow powder 

Melting Point:200-202°C 

Purity:≥99.5%

Uses:Mainly be used in whitening of thermoplastic, polyvinyl chloride(PVC), polypropylene(PP), polyester fiber, paint and ink, etc.


Optical Brightener OB Dosage:

In plastics, the amount of fluorescent whitening agent is usually expressed as a percentage relative to the mass of the plastic. 

The usual amount of transparent plastic is 0.0001%-0.001%, and the amount of white plastic is usually 0.05%-0.1%.


In paint and ink, the amount of fluorescent whitening agent is usually 0.02%-0.05%. When it comes to the specific dosage, 

it is recommended to get some small samples from the fluorescent whitening agent manufacturer, because less fluorescent whitening agent will easily cause whitening The effect is unsatisfactory. Using too much will cause the brightener to separate out, so before determining the dosage, take a sample test to achieve our desired effect.