| abstract |
Photopolymerizable coating and recording materials, such as photopolymer dry film resist materials and photoresist materials, comprising at least one photopolymerizable olefinic compound, which materials contain, as activated photoinitiator system, a carbonyl compound that, when exposed to actinic light, forms free radicals which initiate polymerization, such as benzophenone and benzophenone derivatives, as well as a benzene compound having at least two dichloromethyl groups bound to the benzene nucleus, such as bis(dichloromethyl)-benzene and 2,5-dichloro-1,4-bis(dichloromethyl)benzene, and preferably also a dye which changes color in the presence of acid. The coating and recording materials of the invention exhibit improved curing when exposed to ultraviolet light for the usual periods and can be readily washed out with solvents without any damage to the exposed areas. |