OMNIRAD TPO

OMNIRAD TPO is a highly efficient Type I photoinitiator with low yellowing characteristics.
OMNIRAD TPO exhibits UV absorption maxima at 275 and 379 nm and provides strong through-curing performance.
OMNIRAD TPO is suitable for clear, white, and pigmented UV-curable formulations, including systems designed for UV LED curing.

CAS number: 75980-60-8
EC number: 278-355-8
Molecular formula: C22H21O2P
Molecular weight: 348.4 g/mol

Synonyms: Methanone, (diphenylphosphinyl)(2,4,6-trimethylphenyl)-, di(phenyl)phosphoryl-(2,4,6-trimethylphenyl)methanone, (Diphenylphosphoryl)(mesityl)methanone, 2,4,6-Trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, GENOCURE TPO, UNII-B9EIM2D97X, EINECS 278-355-8, EC 278-355-8, CAS-75980-60-8, MFCD00192110, DTXSID4052502, DTXCID8031075, RefChem:442966, SCHEMBL27651, CHEMBL3561198, VFHVQBAGLAREND-UHFFFAOYSA-, Tox21_303757, diphenyl(2,4,6-trimethylbenzoyl)phosphorus oxide, Phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)-, diphenylphosphino[(2,4,6-trimethylphenyl)carbonyl]-1-one, TRIMETHYLBENZOYL DIPHENYLPHOSPHINE OXIDE [INCI], Lucirin TPO solid, CHIVACURE TPO, DOUBLECURE TPO, ADDITOL TPO

OMNIRAD TPO is a highly efficient Type I photoinitiator with low yellowing characteristics, used in UV-curable formulations.
Upon exposure to UV light, OMNIRAD TPO generates reactive free radicals that initiate the polymerization of unsaturated components, such as acrylates, enabling the formulation to cure into a hardened material.

OMNIRAD TPO's low yellowing characteristics are beneficial in applications where the appearance of the cured material is important.
OMNIRAD TPO is chemically identified as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and is registered under CAS number 75980-60-8.

OMNIRAD TPO applications include stabilized clear UV coatings, fiber glass composites and gel coats.
OMNIRAD TPO is a highly efficient liquid curing agent to initiate radical polymerization of unsaturated resins after exposure to UV light such as those based on a prepolymer – e.g., acrylates and unsaturated polyesters – in combination with mono- or multifunctional monomers as reactive thinners. 

OMNIRAD TPO is well suitable for formulations in which OMNIRAD TPO is used. 
OMNIRAD TPO provides all the handling advantages of a liquid product. 

OMNIRAD TPO is a highly efficient Type I photoinitiator based on phosphine oxide chemistry, chemically identified as diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and is extensively used in UV- and visible-light-curable formulations.
OMNIRAD TPO is supplied as a white to off-white crystalline powder with good thermal stability and excellent solubility in a wide range of acrylate and methacrylate monomers as well as common organic solvents, while remaining insoluble in water.

When exposed to UV or near-visible radiation, typically in the 350–420 nm wavelength range, OMNIRAD TPO undergoes rapid photochemical cleavage, generating highly reactive radical species that efficiently initiate free-radical polymerization.
This mechanism results in very fast curing, high conversion, and excellent through-cure even in thick films or pigmented systems where light penetration is limited.
Due to its low tendency to cause yellowing and its ability to provide clear, durable cured films, OMNIRAD TPO is widely applied in industrial and wood coatings, printing inks, UV-curable adhesives, and photopolymer resins for SLA and DLP 3D-printing technologies, particularly in applications requiring high optical clarity, mechanical performance, and process reliability.

OMNIRAD TPO is a highly efficient, low yellowing, Type I photoinitiator used to initiate radical polymerization of unsaturated oligomers e.g. acrylates, after exposure to UV light. 
OMNIRAD TPO can be used in combination with mono or multi-functional monomers as reactive diluents.

Uses of OMNIRAD TPO:
OMNIRAD TPO is used as a photoinitiator in UV-curable printing inks, inkjet formulations, and graphic arts applications.
OMNIRAD TPO is incorporated into coatings for wood, plastic, and metal substrates to initiate curing upon exposure to UV light.

OMNIRAD TPO is also used in UV-curable 3D printing resins and formulations designed for UV LED curing.
OMNIRAD TPO's curing performance makes it suitable for clear, white, and pigmented systems.

OMNIRAD TPO can be formulated with acrylate oligomers and monofunctional or multifunctional monomers used as reactive diluents.
OMNIRAD TPO is used in clear and pigmented UV-curable varnishes to achieve uniform curing and high optical quality.

OMNIRAD TPO supports deep curing even in formulations containing pigments or fillers that normally limit light penetration.
This makes OMNIRAD TPO suitable for protective and decorative finishes with consistent appearance.

OMNIRAD TPO is also applied in electronic materials such as photoresists, insulating coatings, and encapsulation systems.
OMNIRAD TPO enables precise curing with minimal thermal stress on sensitive electronic components.

OMNIRAD TPO's properties are important for maintaining performance and reliability in electronic devices.
In industrial composite and fiber-reinforced systems, OMNIRAD TPO is used to initiate curing of UV-reactive resin matrices.

OMNIRAD TPO allows controlled polymerization and improved mechanical properties of the final composite.
This application supports lightweight, high-strength materials used in advanced engineering and manufacturing.

OMNIRAD TPO is a photo initiator, used in many kinds of ink industries
OMNIRAD TPO is widely used in UV-curable coatings to achieve fast and efficient polymerization under UV or LED light sources.
OMNIRAD TPO enables rapid surface and through-cure, resulting in hard, durable, and chemically resistant coating films.

Benefits of OMNIRAD TPO:
OMNIRAD TPO provides efficient initiation of UV curing in acrylate-based formulations.
OMNIRAD TPO's strong through-curing performance helps promote curing within the material.

OMNIRAD TPO's low yellowing characteristics help maintain the appearance of cured coatings and printed materials.
OMNIRAD TPO is suitable for clear and white formulations and can also be used in pigmented systems.

OMNIRAD TPO's suitability for UV LED curing gives formulators flexibility when selecting curing equipment.
OMNIRAD TPO can be combined with monofunctional or multifunctional reactive diluents to meet formulation requirements.

Physical and Chemical Properties of OMNIRAD TPO:
OMNIRAD TPO appears as a pale yellow crystalline powder with a faint characteristic odor. 
OMNIRAD TPO exhibits a melting point of 88-92°C and demonstrates excellent thermal stability up to 200°C. 
OMNIRAD TPO shows moderate solubility in common monomers: 15-20% in acrylates, 5-10% in styrene, and limited solubility in water (<0.1 g/L). 

OMNIRAD TPO's unique molecular architecture features both phosphine oxide and benzoyl chromophores, enabling broad absorption in the UV-A range (λmax = 380 nm, ε = 2500 M⁻¹cm⁻¹) with significant tailing into visible light up to 420 nm.

Stability and Reactivity of OMNIRAD TPO:

Chemical stability:
Stable under recommended handling and storage conditions.

Conditions to avoid:
Avoid excessive heat, direct sunlight, and dust accumulation.

Incompatible materials:
Strong oxidizing agents.

Hazardous decomposition products:
Thermal decomposition may release carbon oxides.

Handling and Storage of OMNIRAD TPO:

Safe handling:
Avoid dust generation, inhalation, and contact with skin and eyes.

Hygiene measures:
Wash thoroughly after handling.
Do not eat, drink, or smoke during use.

Storage conditions:
Keep the original container tightly closed in a cool, dry, well-ventilated area.
Protect from sunlight, heat, and ignition sources.
Store locked up.

First Aid Measures of OMNIRAD TPO:

Inhalation:
Move to fresh air and seek medical attention.

Skin contact:
Remove contaminated clothing and wash with soap and water.
Seek medical advice if irritation or rash develops.

Eye contact:
Rinse with water for at least 20 minutes.
Remove contact lenses if easily possible.

Ingestion:
Rinse mouth, do not induce vomiting, and obtain immediate medical attention.
Never give anything orally to an unconscious person.

Notes for physician:
Treat symptomatically.

Firefighting Measures of OMNIRAD TPO:

Suitable extinguishing media:
Water spray, foam, dry chemical powder, or carbon dioxide.

Special hazards:
Airborne dust may form explosive mixtures.
Combustion may release carbon and phosphorus oxides.

Protective equipment:
Wear self-contained breathing apparatus and full protective clothing.

Accidental Release Measures of OMNIRAD TPO:

Personal precautions:
Ventilate the area and wear suitable protective equipment.
Avoid generating or inhaling dust.

Environmental precautions:
Prevent entry into drains and waterways.

Cleanup methods:
Collect mechanically into suitable closed containers.
Dispose of waste according to applicable regulations.

Exposure Controls / Personal Protective Equipment of OMNIRAD TPO:

Engineering controls:
Provide adequate ventilation, eyewash facilities, and safety showers.

Respiratory protection:
Use an approved respirator when ventilation cannot adequately control dust exposure.

Hand protection:
Wear suitable chemical-resistant gloves.

Eye protection:
Wear tightly fitting safety goggles.

Skin protection:
Wear protective clothing.

Hygiene controls:
Wash after handling and clean contaminated clothing before reuse.

Identifiers of OMNIRAD TPO:
Manufacturer: IGM Resins
CAS number: 75980-60-8
Chemical abbreviation: TPO
Product type: Type I photoinitiator. 

Chemical name: Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide
CAS number: 75980-60-8
EC number: 278-355-8
Molecular formula: C22H21O2P
Molecular weight: 348.4 g/mol

Properties of OMNIRAD TPO:
Melting point: 88–92 °C (lit.)
Boiling point: 519.6 ± 60.0 °C (predicted)
Density: 1.12 g/mL at 25 °C (lit.)
Vapor pressure: 0 Pa at 25 °C
Refractive index: n20/D 1.475 (lit.)
Flash point: >230 °F
Storage temperature: sealed in dry conditions, room temperature
Solubility: soluble in methanol
Form: powder to crystal
Color: light yellow to yellow to green
Water solubility: 3.4 mg/L at 20 °C
λmax: 400 nm (DMF) (lit.)
Stability: stable, incompatible with strong oxidizing agents
Cosmetics ingredients functions: nail sculpting
InChIKey: VFHVQBAGLAREND-UHFFFAOYSA-N
LogP: 3.1 at 23 °C

Appearance: White to off-white crystalline powder
Odor: Odorless or very faint odor
Physical state: Solid
Solubility: Insoluble in water; soluble in acrylate monomers and many organic solvents
Melting point: Approximately 90–95 °C
Boiling point: Not applicable (decomposes before boiling)
Density: Approximately 1.2 g/cm³ (at 20 °C)