The Mechanism of E.B. Curing of Thin Films

It has been shown that e.b. curing of acrylates occurs via the attachment of slow electrons to the acrylate groups which ubsequently give radical species leading to polymerisation. For poxy oligomers to be cured by . radiation it is advantageous if he formulation contains ionic photoinitiators eg. onium salts. vidence is presented that slow electrons reduce such salts leading to the production of acid which catalyses polymerisation. By use of TIR spectroscopy the rate of cure, and decomposition of the onium alt and its counterion could be followed. The rate of cure is closely related to the electron scavenging ability of the photoinitiator.