Photoinitiators
Photoinitiator TPO-L
Ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate
The liquid acylphosphine oxide — easiest dosing and widest solubility for UV LED systems.
Product Description
TPO-L is the ethyl ester analog of TPO, supplied as a clear, slightly yellow liquid. The liquid form eliminates melting and dissolution steps, allowing direct low-shear incorporation into acrylate oligomers — a decisive advantage for inkjet formulations that must remain filterable at fine mesh sizes.
Like TPO, its absorption reaches into the visible region, enabling efficient curing under 395–405 nm UV LED arrays as well as conventional mercury lamps. It is particularly valued in clear and slightly pigmented wood coatings, flexographic inks and photocurable 3D printing resins.
Typical addition levels are 1–4 wt% alone or 0.5–2 wt% blended with 184, ITX or amine synergists. Aolong TPO-L is filtered to 0.45 μm before packaging, ensuring clean, particle-free liquids for precision coating and printing equipment.
Key Features
- 100% liquid — no melting, fast dissolution, easy metering
- UV LED responsive (395–405 nm) with good depth cure
- 0.45 μm filtered — suitable for inkjet and precision coating
- Low volatility and excellent storage stability
Applications
- UV inkjet inks and flexographic UV inks
- UV LED wood and plastic coating lines
- Photocurable 3D printing and stereolithography resins
- UV adhesives for glass and electronics assembly
- Clear varnishes and overprint coatings
Specifications
| CAS No. | 84434-11-7 |
|---|---|
| Molecular Formula | C18H21O3P |
| Molecular Weight | 316.33 |
| Appearance | Clear pale yellow liquid |
| Assay (HPLC) | ≥ 99.0% |
| Viscosity (25 °C) | 60 – 90 mPa·s |
| Acid Value | ≤ 1.0 mg KOH/g |
| Water Content (KF) | ≤ 0.2% |
Packaging & Storage
25 kg HDPE pail, 200 kg steel drum or 1 kg aluminum-foil bottle. Store cool, dry and protected from light; shelf life 24 months in original sealed packaging.
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