Optical brightener OB-1

  • Product name: Optical Brightener OB-1
  • Chemical Name: 2,2′- (4,4′-distyryl) bisbenzoxazole
  • C.I.:  393
  • CAS: 1533-45-5
  • Molecular Formula: C28H18N2O2
  • Formula Weight: 414.45
  • Synonyms: Uvitex OB-1, Eastobrite OB-1.
    FBA 393, OB 393, OBA 393, Optical Brightening Agent OB-1.
  • Application: Widely used for brightening polyester resin and fiber, nylon, PP, ABS, PS, HIPS, PA, PC, EVA, rigid PVC, etc.
Send Inquiry


1. Properties of Optical Brightener OB-1

Appearance: Yellowish green crystal powder
Purity: 98.50%
Melting point: 355-360℃
Volatile ≤0.5%
Ash ≤0.03%
Max Absorption Wavelength 374nm (in ethanol)
Max. Emission Wavelength 434nm(in ethanol)

Optical Brightener OB-1 chemical structure

Optical Brightener OB-1 chemical structure

Optical brightener OB-1 is poorly soluble in water, and soluble in alkane, mineral oil, and common organic solvents.

2. Synonyms / Alternative

Uvitex OB-1, Eastobrite OB-1.
FBA 393, OB 393, OBA 393, Optical Brightening Agent OB-1.

3. Packing and Storage

25KG fiber drum lined with a double-layer plastic bag.
Stored in a cool, dry, and ventilated place, the storage term should not exceed 2 years.

4. Features

Optical Brightener OB-1 has excellent thermal stability and high-temperature resistance of 375-400 ℃.
It is the best heat-resistant OBAs among all whitening agents. Therefore, it performs for general high polymers, especially for high melting point engineering plastics such as polysulfone resins. The whiteness of OB-1 is also relatively high, in general, the usage amount is 25-300mg/kg.
It has very Good compatibility with other additives in plastics.
OB-1 has extremely low toxicity and can be used for whitening plastic products for food packaging after strict control.
It has a low price with high performance. It is the most economical OBA for plastics.

5. Common Application and Recommend Dosage

Optical Brightener OB-1 is mainly used for brightening polyester resin and polyester fiber. It can also be used for whitening nylon, PP, ABS, PS, HIPS, PA, PC, EVA, rigid PVC, etc.

Transparent:  0.0025-0.005%.   Commonly used: 0.01-0.05%

Due to the dosage amount being small, please mix thoroughly for the best effect.
When using any UV absorb additive, the dosage of optical brightener OB-1 should be adjusted.

6. Transportation and Safty

Avoid inversion, sunlight, moisture, and crash. Avoid damaging the package.
Non Hazardous. Stock as ordinary chemicals. Wear Protective goggles and gloves while using. And avoid direct contact with skin and eyes. Soap clean if the skin is contaminated.

Shandong Grand Chemical Co., Ltd, is a professional manufacturer of optical brighteners in China.
If you have any inquiries about optical brighteners for plastics, please do not hesitate to contact us via sales@obachemical.com, or WhatsApp: +86 13173009832.

Send Us A Message