Photoinitiator 819 is an efficient free radical photoinitiator, featuring high activity, low odor, good compatibility, low volatility, excellent thermal stability, and high curing efficiency.
When used in combination with photoinitiator 184 and photoinitiator 651, it enhances the light absorption performance and improves the curing efficiency. Its unique high absorption property and non-yellowing characteristic result in excellent curing speed and depth. It is suitable for thick film curing, high coverage white paints, color paints, and inks containing titanium white and pigments.
When used in combination with photoinitiator 651, it is particularly suitable for curing polyester and styrene resins. The general dosage is 1-5%.
Used in Uv-curable varnish and colored paint systems, such as those used for wood, paper, metal, plastic, optical fiber, as well as printing inks and pre-impregnation systems, etc
| Product | UV absorption peaks (nm) | Physical form | Typical positioning |
|---|---|---|---|
| Photoinitiator 819 | 237, 275, 380 | Solid | White pigmented, thick-section, LED-oriented systems |
| Omnirad TPO | 275, 379 | Solid | Clear and pigmented systems, balanced cure response |
| Omnirad TPO-L | 230, 275, 370 | Liquid | Liquid handling, pigmented systems, broader formulation convenience |
In a practical UV-cure comparison, 819 is often chosen when pigmentation, opacity, or film thickness make cure penetration more important than a narrow surface-cure-only design.
Melting Point | 131-135℃ |
Purity | ≥99% |
Loss On Drying | ≤0.2% |
Density | 1.17g/cm3 |
Flash point | 310.6℃ |
Absorption wavelength | 335nm,370nm,405nm |
Photoinitiator 819 is often selected for systems that need a stronger cure window than standard clear-coat photoinitiators. It is not the only answer for every UV formulation, but it is one of the most established options for pigmented and thick-section conditions.
When formulating for UV LED, the absorption profile should be matched to lamp output, film thickness, pigment load, and the target cure speed.
25KG cartons
It is used to initiate radical polymerization of unsaturated resins under UV light. The strongest use cases are white pigmented formulations, glass-fiber-reinforced polyester/styrene systems, outdoor clear coats with light stabilizers, and thick-section curing.
Yes. These names are commonly used for the same chemical: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. The product name changes by supplier or brand, but the core chemistry is the same.
Official product data lists absorption peaks at 237, 275, and 380 nm. That is why the product is often used in UV systems that need support at longer wavelengths and in pigmented formulations.
Yes. Official product guides include Omnirad 819 in recommendations for 365 nm and 395 nm UV LED curing. Matching lamp output and total formulation design is still important for the final cure result.
