Optical brighteners for paints play a vital role in enhancing the visual quality of modern coatings. Also known as fluorescent whitening agents (FWA), fluorescent brightening agents (FBA), or optical brightening agents (OBA), these materials are widely used in paints, coatings, inks, plastics, and polymers to achieve higher whiteness, improved brightness, and superior color clarity.
By using optical brighteners for paints, manufacturers can effectively offset yellow tones, improve transparency, and increase the overall brilliance of both white and colored coatings—without increasing pigment loading.
Working Principle of Optical Brighteners for Paints
The whitening mechanism of optical brighteners is based on fluorescence. Optical brighteners absorb invisible ultraviolet (UV) light in the 300–380 nm range and re-emit it as visible blue light (typically 420–480 nm).
This emitted blue light compensates for the natural yellowish hue of resins, solvents, and pigments. As a result, the human eye perceives the coating as whiter, brighter, and cleaner, delivering an immediate and long-lasting visual enhancement.
Optical Brightener OB for Paints and Coatings
Optical Brightener OB is one of the most widely used optical brighteners for paints due to its excellent compatibility, stability, and whitening efficiency.
Product Identification
- Trade Name: Optical Brightener OB
- Alternatives: Tinopal OB CO, Uvitex OB, Huntsman OB
- C.I. No.: 184
- CAS No.: 7128-64-5
- Chemical Name: 2,5′-Bis[2-(5-tert-butyl-2-benzoxazolyl)]thiophene
- Molecular Formula: C₂₆H₂₆N₂O₂S
- Molecular Weight: 430
Technical Specifications
- Appearance: Slight greenish-yellow powder
- Melting Point: 200–202 °C
- Purity: ≥99%
Key Advantages of Optical Brighteners for Paints and Coatings
1. Excellent Solubility
Optical Brightener OB dissolves easily in common organic solvents at room temperature, including xylene, toluene, methanol, and acetone, ensuring uniform dispersion in paint formulations.
2. Easy Processing
It can be added directly during paint production along with pigments and other additives, requiring only thorough mixing to achieve optimal performance.
3. Improved Transparency and Weather Resistance
Optical brighteners for paints enhance the transparency of clear coatings while adding brilliance to colored systems. Their blue fluorescence improves color vividness without masking underlying shades.
4. High Efficiency at Low Dosage
Only 200 g per ton of paint can increase whiteness by approximately 10 units, making OB a highly cost-effective solution.
5. Environmentally Compliant
Optical Brightener OB has passed RoHS testing and SVHC screening by SGS, making it a safe and environmentally friendly additive for modern paint and coating applications.
Typical Applications
Optical brighteners for paints are widely used in:
- Architectural and industrial paints
- Clear and pigmented coatings
- Printing inks
- PVC, PP, and thermoplastic materials
- Polyester fibers and specialty coatings
Why Choose Shandong Grand Chemical?
Shandong Grand Chemical Co., Ltd. has decades of experience supplying optical brighteners for paints to large and medium-sized coating and paint manufacturers worldwide. Our technical expertise ensures stable quality, reliable performance, and professional application support.
📩 Contact us for product data sheets, samples, or technical guidance:
Email: sales@obachemical.com
WhatsApp: +86 13173009832