Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide
CAS 75980-60-8
EC 278-355-8
Formula C22H21O2P
MW 348.37 g/mol
Catalysts & Catalyst Precursors Coatings, Adhesives, Sealants & ElastomersPrinting & PackagingPlastics & Polymers CatalysisPolymerization InitiationCross-linking & Curing
Description
Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, commonly known as TPO and sold under trade names including Irgacure TPO, Lucirin 8893X, Chivacure TPO, SPEEDCURE TPO, and SP-2,4,6, is a Type I photoinitiator with CAS number 75980-60-8. It carries no assigned E-code and belongs to the acylphosphine oxide class of photoinitiators.
TPO generates reactive phosphinoyl radicals upon exposure to UV light in the 370-420 nm range, triggering free-radical polymerization in UV-curable systems. It is used in radiation-curable coatings and printing inks where deep cure and surface cure under visible-range UV are required, and in adhesive and sealant formulations where rapid cross-linking under LED or mercury lamp sources is specified.
TPO is supplied as a white to cream powder and is available in standard industrial grades compliant with REACH registration requirements. Procurement quantities typically range from kilogram to metric-ton scale. Buyers should confirm supplier documentation for REACH compliance and any applicable regional chemical notification obligations before import.
TPO generates reactive phosphinoyl radicals upon exposure to UV light in the 370-420 nm range, triggering free-radical polymerization in UV-curable systems. It is used in radiation-curable coatings and printing inks where deep cure and surface cure under visible-range UV are required, and in adhesive and sealant formulations where rapid cross-linking under LED or mercury lamp sources is specified.
TPO is supplied as a white to cream powder and is available in standard industrial grades compliant with REACH registration requirements. Procurement quantities typically range from kilogram to metric-ton scale. Buyers should confirm supplier documentation for REACH compliance and any applicable regional chemical notification obligations before import.
Physical Properties
| Melting Point | 87-89 °C |
| Boiling Point | 519.6±60.0 °C(Predicted) |
| Density | 1.27 g/cm³ |
| Flash Point | >230 °F |
| Appearance | white or cream powder |
| Color | Light yellow to Yellow to Green |
| Form | powder to crystal |
| Water Solubility | 3.4mg/L at 20℃ |
| Vapor Pressure | 0Pa at 25℃ |
| Refractive Index | n 20/D 1.475(lit.) |
| Log P | 3.1 at 23℃ |
Trade & Regulatory
| HS Code | 29319090 |
| UN Number | 3077 |
| ADR Class | 9 |
| Packing Group | III |
| Storage Class | 11 - Combustible Solids |
| WGK (Germany) | 2 |
Other Names
SP-2,4,6Irgacure TPOChivacure TPOSPEEDCURE TPOLucirin 8893XLucirin LR 8893Lucirin LR 8728LABOTEST-BB LT00452354Diphenyl(2,4,6-trimethylbenzoyl)
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