US Patent 7544462 Radiation-sensitive composition and elements with basic development enhancers

Radiation-sensitive compositions can be used to prepare positive-working imageable elements useful for example to make lithographic printing plates. The compositions include an aqueous alkaline solvent soluble polymeric binder that includes a phenolic resin (such as a novolak) or a poly(vinyl acetal). The compositions also include a developability-enhancing composition comprising one or more basic nitrogen-containing organic compounds. The radiation-sensitive composition can be coated as an imageable layer that further includes a radiation absorbing compound that is, for example, sensitive to infrared radiation.