Patent ID: 8828648
Filing Date: 2014-09-09
Classification: B41C,G03F

Abstract:
1. A method of making a planographic printing plate, comprising in the following order: subjecting a planographic printing plate precursor, which comprises a support and a positive-working image recording layer provided on the support, to image-wise exposure, the positive-working image recording layer comprising: a lower layer comprising a (A) water-insoluble and alkali-soluble resin and an (B) an infrared ray absorbing agent; and an upper layer comprising a (C) water-insoluble and alkali-soluble polyurethane resin and a (D) polyorganosiloxane; and developing the planographic printing plate precursor using an alkaline aqueous solution which comprises at least one of a compound represented by the following Formula (1) or a compound represented by the following Formula (2) and has a pH of from 8.5 to 10.8: wherein, in Formula (1), R in Formula (2), R