Photoinitiator TPO CAS 75980-60-8

CAS: 75980-60-8

MF: C22H21O2P

MW: 348.37

EINECS: 278-355-8


Photoinitiator TPO, chemically known as Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, is an highly effective photoinitiator. It can be used in UV curable formulations for inks, coatings, and adhesives on surface of wood, metal, plastic, paper, and glass fiber, for both surface and deep-layer curing. TPO Photoinitiator is especially suitable for pigmented system and deep-layer curing which requires low yellowing, low volatility, low odor.

BoldChem supplies high quality photoinitiator TPO (CAS No. 75980-60-8) with very competitive price.

Properties of Photoinitiator TPO

Photoinitiator TPO is a highly efficient type I photoinitiator with absorption over a long wavelength range. After exposure to light, photoinitiator TPO can produce two free radicals – benzoyl and phosphoryl, both of which can initiate polymerization, resulting in a fast curing rate.

TPO Photoinitiator is yellowish crystalline powder with below physical properties:

UV spectrum of photoinitiator TPO
UV spectrum of photoinitiator TPO

Density:  1.12 g/mL at 25 °C(lit.)
Flash Point:  >230 °F
Melting Point:  88-92 °C(lit.)
Boiling Point:  519.6ºC at 760 mmHg
Refractive Index:  n20/D 1.475(lit.)

TPO Photoinitiator has a wide range of long UV wavelength absorption with absorption peaks at 269nm, 298nm, 379nm, 393nm in methanol solution. It can absorb light with wavelength range from 250 nm all the way up to 430nm, longer than what conventional photoinitiators can do, which makes it suitable for many applications, especially perfect to be used in pigmented photocuring systems.

Applications of Photoinitiator TPO

TPO photoinitiator can be used for UV curing coatings, screen printing inks, lithographic printing inks, flexographic printing inks, wood coatings, printing inks, UV curing adhesives, optical fiber coatings, etc. particularly suitable for curing pigmented systems and thick-layered coatings.

Photoinitiator TPO has low post polymerization effect and no residue, which makes it perfect to be used for transparent or white coatings, especially for products with low yellowing and low odor requirements.

TPO photoinitiator exhibits good solubility in some common UV formulations such as acrylate and unsaturated polyester systems. It has high initiation efficiency when used alone in unsaturated polyester containing styrene system. For acrylic ester systems, especially colored systems, it usually need to be used in conjunction with amines or acrylamide.

Photoinitiator TPO can be compounded with other photoinitiators to achieve complete curing effect. It is used with 184 in adhesive products.

The recommended addition amount for TPO photoinitiator is within 0.5-4% by w/w. The specific addition dosage should be based on actual experimental results.

Packaging of Photoinitiator TPO

Normally, TPO Photoinitiator is packed in 20 kg/cardboard drums, inner packed with PE bag, also can be packed according to customer requirements.

Photoinitiator TPO have no irritation to human skin, therefore, can be transported safely. No special safety measures are required, just follow the general chemical operation specifications.

Storage of Photoinitiator TPO

Photoinitiator TPO should be sealed and stored in a dry, cool, dark place. It should be kept at low or room temperature to avoid sunlight and exposure to strong oxidants. TPO Photoinitiator has a shelf life of at least two years in a sealed container at 20°C in a dark ventilated place.