Abstract: Provided are a planographic printing plate precursor including: a support; and an image recording layer provided on the support, in which the image recording layer contains an infrared absorbing agent, a polymerization initiator, a polymerizable compound containing a hydrogen bonding group, and a hard polymer particle containing at least one group selected from the group consisting of a urethane group, a urea group, an imide group, an amide group, and a sulfonamide group on the surface of the hard polymer particle, and a number average primary particle diameter of the hard polymer particle is in a range of 0.01 to 1 ?m; and a plate-making method for a planographic printing plate obtained by using the planographic printing plate precursor.

Abstract: Provided are a thermal fusion-type lithographic printing plate precursor in which the visibility is excellent, ablation during laser exposure is suppressed, and the contamination of dampening water and printing ink during on-machine development is suppressed by a lithographic printing plate precursor having a support and an image-recording layer, in which the image-recording layer is capable of forming an image by infrared laser exposure, a non-exposed portion of the image-recording layer is removable by at least one of dampening water and printing ink on a printer, and the image-recording layer contains (1) a color developing system in which a hue change generated by infrared laser exposure is ?a/?b?0.6 and (2) 70% by mass or more of a thermoplastic polymer particle with respect to a solid content of the image-recording layer and a plate-making method in which the thermal fusion-type lithographic printing plate precursor is used.

Abstract: Provided are a planographic printing plate precursor including: a support; and an image recording layer provided on the support, in which the image recording layer contains an infrared absorbing agent, a polymerization initiator, a polymerizable compound containing a hydrogen bonding group, and a hard polymer particle containing at least one group selected from the group consisting of a urethane group, a urea group, an imide group, an amide group, and a sulfonamide group on the surface of the hard polymer particle, and a number average primary particle diameter of the hard polymer particle is in a range of 0.01 to 1 ?m; and a plate-making method for a planographic printing plate obtained by using the planographic printing plate precursor.