Photoinitiator 819 (BAPO) for UV Ink
CAS Number: 162881-26-7
Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO, PI-819) is the leading bisacylphosphine oxide photoinitiator for UV offset, flexo, and digital inks, generating two radical pairs per molecule upon UV excitation for outstanding photoinitiation efficiency. Its wide absorption extending to 470 nm enables deep cure even in heavily pigmented magenta and cyan inks, and its compatibility with LED sources makes it essential in modern UV LED printing systems.
Technical Specifications
| appearance | Yellow to greenish-yellow powder |
| purity (%) | ≥98 |
| moisture (%) | ≤0.3 |
| absorption max (nm) | 295, 370, 400–470 |
| melting point (°C) | 127–133 |
Applications
- UV offset ink deep-cure photoinitiator
- UV LED flexo inks for food packaging
- UV digital inkjet inks (pigmented systems)
- Deeply pigmented UV screen-printing inks
- UV-curable coating and varnish systems
Key Features
- Bisacylphosphine generates 2 radical pairs per molecule for maximum efficiency
- Wide absorption to 470 nm enables cure under visible LED light
- Outstanding deep-cure in magenta, cyan, and white UV inks
- Low required dosage (0.5–3%) due to exceptional quantum yield
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CAS Number
162881-26-7
Category
Printing Ink ChemicalsAvailability
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