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Study of radical generated from coumarin dye-sensitized photo-initiator systems in high-speed photopolymer coating layers using laser flash photolysis

✍ Scribed by Toshiyuki Urano; Etsuko Hino; Hiroto Ito; Makoto Shimizu; Tsuguo Yamaoka


Publisher
John Wiley and Sons
Year
1998
Tongue
English
Weight
136 KB
Volume
9
Category
Article
ISSN
1042-7147

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✦ Synopsis


Radical generation from photoinitiation systems containing carbonylbiscoumarin dye with a radical-generating reagent, 3,3'-carbonylbis[7-(diethylamino)-2H-1-benzopyran-2-one] (KCD-DA), with 2,2'-bis(2-chlorophenyl)-4,4'5,5'-tetraphenyl-1, 1'-bi-1H-imidazole (BI) in a poly(methyl methacrylate) film has been investigated by laser flash photolysis using a total reflection cell.

Imidazolyl radical (ImÁ) was predominantly generated from carbonylbiscoumarin triplet-sensitized decomposition of BI, the quantum yield, Φ o ImÁ of ImÁ at an infinite concentration of BI was measured, Φ o ImÁ = 1.3. The high quantum yield, Φ o ImÁ , implies an efficient KCD-DA triplet-sensitized photoinitiation system containing BI.