: TPO - Lambson

1 UV CURING | UV ABSORBERS | PVP/PVPP | optical brighteners | ANTI OXIDANTS Lambson Limited Lamro House 603 Thorp Arch Estate Wetherby West Yorkshire LS23 7FS Tel +44 (0) 1937 840 150 Fax +44 (0) 1937 840 151 Email Web Chemical Name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide CAS Number: 75980-60-8 EC Number: 278-355-8 Molecular Weight: General Information Speedcure TPO is an extremely efficient Type I homolytic photoinitiator, which absorbs UV light at longer wavelengths, thus making it particularly suitable for curing pigmented formulations.

2 Speedcure TPO undergoes a photo-bleaching reaction that allows the effective curing of thick films. Date issued: 09-09-2011 Page 1 of 2 Applications Wood coatings and filler Glass fibre reinforced polyester laminates Manufacture of printing plates Pigmented printing inks : TPO | Leading the way in product innovation Technical Data Sheet Features and Benefits Absorbs long wavelength UV to undergo bond cleavage providing very reactive radicals (379 nm). Known to photo-bleach . Adding an amine such as Speedcure EDB or EHA reduces oxygen inhibition.

3 Thioxanthones can act as sensitizers for this product. Excellent for curing white pigmented systems. Low yellowing. Good for curing thick films. Reduced discolouration. Long shelf life. Thermally stable. (nm) : TPO Date issued: 09-09-2011 Page 2 of 2 UV Absorption Spectrum Physical Properties Appearance Pale yellow crystalline powder Assay 97% min Acidity mg KOH/g max (typical mg KOH/g) Melting point (range) 87 - 94 C Loss on drying w/w max Ash w/w max at 267 nm 64 (Solvent: methanol) at 298 nm 55 (Solvent: methanol) Storage Stable for at least 2 years at 20 C in a sealed container in the dark.

4 Transport Classification (EUROPE AND USA) HAZARDOUS Class 9, Packing Group III, UN3077 The information provided in these notes is given in good faith and is based on the material available at the time of writing. Lambson Limited cannot be held responsible for any claims for loss or damage arising out of the application of this information or any part of it. Health and Safety Information A full Safety Data Sheet is available on request. Concentration Methanol, 1cm path length