Polymerizable composition and planographic printing plate precursor

摘要

The present invention provides a planographic printing plate precursor including on a support a photosensitive layer that contains a polymerizable composition containing a specific binder polymer having a repeating unit of formula (I), an infrared absorbent, a polymerization initiator and a polymerizable compound, wherein R¹ represents a hydrogen atom or a methyl group; R² represents a linking group which includes two or more atoms selected from a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom and a sulfur atom and has a number of atoms of 2 to 82; A represents an oxygen atom or -NR³- in which R³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms; and n represents an integer of 1 to 5. The invention also provides a planographic printing plate precursor provided with a specific photosensitive layer with respect to an alkaline developer.