Uniform color distribution is the most fundamental requirement for printing inks. Additionally, since inks are often exposed to outdoor environments for extended periods, exceptional weather resistance is essential. Based on these two critical criteria, optical brighteners used in ink applications must deliver outstanding compatibility and weatherability.
For this specific application, Jinan Tonex recommends Optical Brightener OB.
Chemical Properties of Optical Brightener OB
| Property | Specification |
|---|---|
| Chemical Name | 2,5-Thiophenediylbis(5-tert-butyl-1,3-benzoxazole) |
| Molecular Formula | C₂₆H₂₆N₂O₂S |
| Molecular Weight | Approx. 430.6 g/mol |
| CAS Number | 7128-64-5 |
| Appearance | Yellowish-green crystalline powder |
| Melting Point Range | 196 – 203°C; other sources indicate 192 – 208°C |
| Decomposition Temperature | > 350°C, indicating excellent thermal stability |
| Density (20°C) | Approx. 1.26 g/cm³ |
| Maximum UV Absorption Wavelength | Approx. 375 nm |
| Maximum Fluorescence Emission Wavelength | Approx. 435 nm |
This product features high whiteness, excellent brilliance, good dispersibility, and superior weather resistance, effectively preventing yellowing or fading even after prolonged exposure.
The recommended dosage of Optical Brightener OB in ink formulations is extremely low-only 0.02% to 0.05% (200 to 500 grams per metric ton of ink). At such a minimal cost, it delivers significant improvements in whiteness, brightness, color vividness, and weatherability.
The application process is also straightforward: simply add OB during the ink manufacturing stage and mix thoroughly to achieve the desired whitening effect.