A heat mode sensitive imaging element for making positive working printing plates

摘要

According to the present invention there is provided a heat mode imaging element for providing a lithographic printing plate consisting of a lithographic base with a hydrophilic surface and a top layer that is sensitive to IR-radiation, comprises a polymer soluble in an aqueous alkaline solution, and is unpenetrable for an aqueous alkaline developer, characterized in that said top layer comprises a polysiloxane surfactant.