SILICATE-FREE DEVELOPER COMPOSITIONS

摘要

A silicate-free alkaline aqueous developer composition has a pH of at least 12 and comprises a metal cation M2+ selected from barium, calcium, strontium, and zinc cations, and a chelating agent that has a complex formation constant (log K) for the metal cation of at least 3.5 and less than or equal to 4.5, and a log K for aluminum ion that is 7 or less. This developer composition can be used to process positive-working lithographic printing plate precursors to provide lithographic printing plates.