| 摘要 |
A method of making a planographic printing plate, the method includes exposing, to infrared light, a planographic printing plate precursor including a recording layer provided on a substrate; and developing the precursor using an aqueous alkaline solution, in which the recording layer comprises a copolymer containing a structural unit derived from (meth)acrylonitrile and a structural unit derived from styrene, a water-insoluble and alkali-soluble resin, and an infrared absorbing agent, the solubility of the recording layer in the aqueous alkaline solution being increased by the exposure, and in which the aqueous alkaline solution has a pH of 8.5 to 10.8 and contains a betaine-based amphoteric surfactant and an ammonium salt represented by Formula (I): wherein, R1, R2, R3, and R4 each independently represent an alkyl or aryl group; the total number of carbon atoms in R1, R2, R3, and R4 is not more than 20; and X- represents a counter anion.
|
