Photoinitiator TPO-L (Ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate)

CAS Number: 84434-11-7
EC Number: 282-810-6
 Molecular Formula: C₁₈H₂₁O₃P
 Molecular Weight: 316.33 g/mol

Chemical & Physical Properties

Key Features & Advantages

Technical Benefits

• Broad Spectrum Absorption: Absorbs UV light at 299 nm and visible light at 366 nm

• Low Yellowing: Minimizes discoloration in cured products, ideal for white and clear coatings

• Low Odor: Suitable for odor-sensitive applications

• High Efficiency: Rapidly generates reactive species for fast curing

• Liquid Form: Easy to handle and incorporate into formulations

Photochemical Properties

• Absorption Wavelength: 290-400 nm with maxima at 299 nm and 366 nm

• Quantum Yield: 0.65 for radical generation

• Initiation Mechanism: Undergoes α-cleavage upon light exposure, producing reactive benzoyl and phosphinoyl radicals

Applications

Printing Inks

• Use Cases: UV-curable offset, flexographic, and screen printing inks

• Benefits:

• Enables high-speed printing lines with curing times <1 second

• Improves scratch resistance and adhesion to substrates

• Maintains print quality on various surfaces (paper, plastic, metal)

• Typical Loading: 1-5% by weight of formulation

Coatings & Varnishes

• Use Cases: UV-curable wood coatings, industrial protective coatings, automotive clear coats

• Benefits:

• Achieves fast surface cure and through-cure even in thick films

• Enhances chemical resistance and mechanical properties

• Works effectively with visible light curing systems

• Typical Loading: 2-6% by weight of formulation

Adhesives & Sealants

• Use Cases: Medical device adhesives, electronic encapsulation materials, optical bonding

• Benefits:

• Enables rapid bonding in seconds under UV/visible light

• Provides high bond strength with excellent transparency

• Meets biocompatibility requirements for medical applications

• Typical Loading: 0.5-4% by weight of formulation

3D Printing

• Use Cases: 3D printing resins

• Benefits:

• Enables high-resolution printing with layer thickness <50 μm

• Supports both UV and visible light curing systems

• Improves mechanical properties of printed parts

• Typical Loading: 0.5-3% by weight of formulation

Electronics Industry

• Use Cases: Photoresists, PCB solder masks, encapsulation materials

• Benefits:

• Enables high-resolution patterning in microelectronics

• Provides excellent thermal stability and insulation properties

• Supports low-temperature curing processes

• Typical Loading: 1-4% by weight of formulation

Textile Industry

• Use Cases: UV-curable textile finishes, fiber modification agents

• Benefits:

• Enhances fabric properties without affecting hand feel

• Improves wrinkle resistance and color fastness

• Enables eco-friendly finishing processes

• Typical Loading: 0.2-2% by weight of formulation