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2,4,6-trimethylbenzoyl diphenylphosphine oxide

CAS Number
75980-60-8
EC Number
278-355-8
Chemical Formula
C22H21O2P
Molecular Weight
348.4 g/mol

Description

2,4,6-Trimethylbenzoyl diphenylphosphine oxide , commonly known as TPO, is a monoacylphosphine oxide photoinitiator that triggers free-radical polymerization upon UV or visible light exposure. It is used across UV-curable systems to initiate rapid crosslinking and curing without thermal activation. In UV-curable coatings for wood, metal, and plastic substrates, TPO delivers fast surface cure and low yellowing, making it a preferred choice for clear and pigmented finishes. This chemical, identified by CAS 75980-60-8 , is essential for modern industrial coating processes. Printing inks, particularly LED-UV and broad-spectrum UV inkjet and offset formulations, rely on TPO for its strong absorption in the 380–420 nm range. This specific absorption profile enables high-speed curing on press, which is vital for high-volume commercial printing operations. In adhesives and sealants, it supports through-cure in acrylate-based systems where depth of cure and bond strength are critical performance requirements. This ensures that the structural integrity of the bond is maintained even in thick layers or opaque formulations. Dental composites and optical fiber coatings also use TPO where controlled, rapid photopolymerization is required in precision applications. Its ability to cure effectively under visible light makes it a versatile component in medical and telecommunications manufacturing. TPO is supplied as a light yellow to yellow crystalline powder. Standard commercial grades are available at high purity, typically ≥98–99%, for industrial and specialty applications requiring consistent chemical performance and stability. It is commonly offered in technical and photoinitiator-grade specifications to meet various industrial needs. Packaging options range from kilogram quantities to bulk drums suited for large-scale formulation operations and global supply chain requirements. Contact us for supply of 2,4,6-trimethylbenzoyl diphenylphosphine oxide Request Quote

Other Names (Synonyms)

Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide | diphenylphosphoryl-(2,4,6-trimethylphenyl)methanone | (2,4,6-Trimethylbenzoyl)diphenylphosphine oxide

Key Technical Features

  • High Purity Grade standard
  • Consistent Batch Quality
  • Full Regulatory & REACH Support
  • Global Logistics Network enabled

Physical Properties

Melting Point87-89 °C
Boiling Point519.6±60.0 °C(Predicted)
Density1.27 g/cm³
Flash Point>230 °F
Appearancewhite or cream powder
ColorLight yellow to Yellow to Green
Formpowder to crystal
Water Solubility3.4mg/L at 20℃
Vapor Pressure0Pa at 25℃
Refractive Indexn 20/D 1.475(lit.)
Log P3.1 at 23℃

Safety & Handling

Danger
GHS07· IrritantGHS08· Health HazardGHS09· Environment

Hazard Statements

H317May cause an allergic skin reaction

Trade & Regulatory

HS Code29319090
UN Number3077
ADR Class9
Packing GroupIII
Storage Class11 - Combustible Solids
WGK (Germany)2