For its extensive usability and excellent performance, Optical Brightening Agent OB is widly applied in coatings, paintings, inks, normal plastics(except some high temperature plastics), etc. Its popularity, though, also cause the appearance of many different purity items in market. Low purity products not only will low down the whitening effect, but also have possibility to hurt the final production.
Knowing how to veryfy the purity of OB is of great significance!
The normal appearance of pure OB is light green powder. There are companies who add pigments in OB which will show a more beautiful appearance. However, this change will low down its weatherability.
The normal dosage of pure OB is 0.01-0.05%. Adding more than this dosage, the product may not be the pure on.
Whitening effect is the final goal of using OB. Making an application test and comparing the whiteness will reveal the purity.
Add 6 grams OB into 100ml xylnene(seperate in three times) and observe the transparency of the solution. Pure OB will have transparent appearance.
5. Melting Point
The melting point of pure OB is 201-202℃. Using melting point apparatus to test sample.
Above five methods are just basic ways to verify whether the OB you have got is pure or not. For more detailed and specific result, pls do not hesitate to connect with Glory Chemical. We are happy to provide you free testing service.