Speciality Chemicals

Photoinitiator TPO

  • CAS No.75980-60-8
  • GradeIndustrial / Pharmaceutical
  • Availability● In Stock

Photoinitiator TPO is a high-efficiency Type I free radical UV photoinitiator ideal for colored systems and thick-film curing in inks, coatings, and adhesives.

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Product Technical Details

Product Overview

Photoinitiator TPO, chemically known as diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, is a high-performance Type I free radical photoinitiator widely employed in ultraviolet (UV) curable formulations. With its broad absorption spectrum extending into the near-UV range, TPO excels in applications requiring deep cure, especially in pigmented or opaque systems where conventional photoinitiators may underperform.

Specifications

Molecular FormulaC₂₂H₂₁O₂P
Molecular Weight348.38 g/mol
Melting Point88–92 °C
Density1.12 g/mL at 25 °C
Boiling Point519.6 °C at 760 mmHg
Refractive Indexn²⁰/D 1.475
Assay≥99%
Volatile Matter≤0.30%
UN NumberUN3077
Transport Hazard ClassClass 9 (Environmentally Hazardous Substance, Solid, N.O.S.)
Packing GroupIII

Industrial Applications

Photoinitiator TPO demonstrates exceptional solubility in common UV-curable resins, including acrylates and unsaturated polyester systems. It is particularly valued for its rapid curing speed and effectiveness in demanding applications such as screen printing inks, lithographic and flexographic inks, wood coatings, metal and plastic surface finishes, and industrial adhesives. Its ability to initiate polymerization efficiently—even in thick or heavily pigmented films—makes it a preferred choice for formulators seeking robust performance without compromising on cure depth or surface quality.

  • Can be used alone or synergistically with other photoinitiators to optimize cure profiles.
  • Recommended dosage: 0.5–4% w/w, depending on formulation and application requirements.
  • Especially effective in colored and white UV-curable systems due to extended absorption characteristics.

Handling and Storage

Store in a cool, dry, and well-ventilated area. Keep container tightly closed to prevent moisture uptake and degradation. Standard industrial hygiene practices should be followed during handling.