Photoinitiators
Photoinitiator 819
Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide
The premium bis-acylphosphine oxide for maximum depth cure in demanding, opaque systems.
Product Description
Photoinitiator 819 (BAPO) is the premium acylphosphine oxide featuring two chromophore groups per molecule. It provides the deepest penetration and cure of any commercial initiator, making it the reference choice for white paints, thick bond lines and highly pigmented systems where standard initiators fail to cure through.
With absorption extending past 400 nm, 819 is fully compatible with UV LED curing units and delivers complete through-cure in thick films up to several hundred micrometers. Its two-step photolysis yields four radical species per molecule, giving exceptional efficiency at low loadings of 0.5–2 wt%.
Aolong 819 is produced to ≥98.0% HPLC assay with strict control of mono-acyl by-products that compromise depth cure, ensuring formulators receive the full performance the chemistry promises.
Key Features
- Deepest through-cure of all commercial photoinitiators
- Fully UV LED compatible (385–405 nm)
- High efficiency — four radicals per molecule at low dosage
- Low volatility and excellent compatibility in LED inks
Applications
- White and opaque industrial UV coatings
- Thick-film UV adhesives and potting compounds
- Deep-cure 3D printing and dental resins
- UV LED curing lines for electronics
- Pigmented UV gel and screen inks
Specifications
| CAS No. | 162881-26-7 |
|---|---|
| Molecular Formula | C26H27O3P |
| Molecular Weight | 418.47 |
| Appearance | White to off-white crystalline powder |
| Assay (HPLC) | ≥ 98.0% |
| Melting Point | 131 – 135 °C |
| Loss on Drying | ≤ 0.5% |
| Acid Value | ≤ 1.0 mg KOH/g |
Packaging & Storage
25 kg fiber drum with PE liner, 1 kg aluminum-foil sample bag. Store cool, dry and protected from light; shelf life 24 months in original sealed packaging.
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