Provided is a lithographic printing plate precursor having a support, an image-recording layer, and an overcoat layer in this order, in which the image-recording layer contains a polymerization initiator, a polymerizable compound, and particles, and the overcoat layer contains a discoloring compound. Also provided is a method of preparing a lithographic printing plate or a lithographic printing method that uses the lithographic printing plate precursor.

Provided is a lithographic printing plate precursor having a support, an image-recording layer, and an overcoat layer in this order, in which the image-recording layer contains a polymerization initiator, a polymerizable compound, and particles, and the overcoat layer contains a discoloring compound. Also provided is a method of preparing a lithographic printing plate or a lithographic printing method that uses the lithographic printing plate precursor.

The purpose of the present invention is to provide a planographic printing plate precursor which suppresses bleeding or transferring of a substance over time while maintaining edge stain preventing performance, a plate-making method of a planographic printing plate, and a printing method using the planographic printing plate. The planographic printing plate precursor includes a support; and an image recording layer formed on the support, in which layer arrangement described in any one of the following i to iv is provided, a hydrophilizatioin agent layer containing a hydrophilization agent is provided in a region in a specific position of the layer arrangement from the end portion of the planographic printing plate precursor to a portion inside the end portion by 1 cm, and the image recording layer includes an infrared absorbing agent and a specific radical polymerizable compound. i: a mode in which the support layer and the image recording layer are provided in this order. ii: a mode in which the support layer, an undercoat, and the image recording layer are provided in this order. iii: a mode in which the support layer, the image recording layer, and a protective layer are provided in this order. iv: a mode in which the support layer, the undercoat, the image recording layer, and the protective layer are provided in this order.

The purpose of the present invention is to provide a planographic printing plate precursor which suppresses bleeding or transferring of a substance over time while maintaining edge stain preventing performance, a plate-making method of a planographic printing plate, and a printing method using the planographic printing plate. The planographic printing plate precursor includes a support; and an image recording layer formed on the support, in which layer arrangement described in any one of the following i to iv is provided, a hydrophilizatioin agent layer containing a hydrophilization agent is provided in a region in a specific position of the layer arrangement from the end portion of the planographic printing plate precursor to a portion inside the end portion by 1 cm, and the image recording layer includes an infrared absorbing agent and a specific radical polymerizable compound. i: a mode in which the support layer and the image recording layer are provided in this order. ii: a mode in which the support layer, an undercoat, and the image recording layer are provided in this order. iii: a mode in which the support layer, the image recording layer, and a protective layer are provided in this order. iv: a mode in which the support layer, the undercoat, the image recording layer, and the protective layer are provided in this order.

An on-machine development lithographic printing plate precursor includes an image-recording layer on an aluminum support having an anode oxide film, wherein an end portion of the lithographic printing plate precursor has a shear droop shape, the image-recording layer contains a compound having a support adsorptive property, having a molecular weight of 1,000 or less, and not having an unsaturated double bond group in a molecule, and a content of the compound is substantially the same in a plane of the image-recording layer.

A method for fixing and treating a flexible plate on a drum includes: providing a flexible plate comprising a support layer made of a first material and at least one additional layer made of a second material which is different from the first material, wherein one or more thin film side wings are connected to one or more sides of the flexible plate. The one or more thin film side wings have a thickness which is at least 5 times smaller than the thickness of the flexible plate. The method further includes positioning the flexible plate on the drum such that the lower face of each thin film side wing of the flexible plate covers at least one vacuum suction opening, and performing a treatment on at least one layer of the flexible plate while rotating the drum.

A lithographic printing plate precursor including a hydrophilized aluminum support, and a water-soluble or water-dispersible negative type image recording layer provided on the aluminum support, in which an arithmetic average height Sa of a surface of an outermost layer on a side where the image recording layer is provided is in a range of 0.3 μm to 20 μm; a method of producing a lithographic printing plate precursor; a lithographic printing plate precursor laminate formed of the lithographic printing plate precursor; a plate-making method for a lithographic printing plate; and a lithographic printing method.

A lithographic printing plate precursor including a hydrophilized aluminum support, and a water-soluble or water-dispersible negative type image recording layer provided on the aluminum support, in which an arithmetic average height Sa of a surface of an outermost layer on a side where the image recording layer is provided is in a range of 0.3 μm to 20 μm; a method of producing a lithographic printing plate precursor; a lithographic printing plate precursor laminate formed of the lithographic printing plate precursor; a plate-making method for a lithographic printing plate; and a lithographic printing method.

Provided are an on-press development type lithographic printing plate precursor having a support and an image-recording layer on the support in which the image-recording layer contains a coloring compound capable of having a coloring reaction with a decomposition product generated by exposure of the image-recording layer, and an on-press development type lithographic printing plate precursor having a support and an image-recording layer on the support in which the image-recording layer contains a compound represented by Formula 1C or Formula 2C and an electron-donating polymerization initiator. In Formula 1C and Formula 2C, R.sup.1C to R.sup.4C each independently represent a monovalent organic group, L.sup.1C and L.sup.2C each independently represent a divalent organic group, A.sup.C represents OH or NR.sup.5CR.sup.6C, and R.sup.5C and R.sup.6C each independently represent a monovalent organic group.

##STR00001##

Provided are an on-press development type lithographic printing plate precursor having a support and an image-recording layer on the support in which the image-recording layer contains a coloring compound capable of having a coloring reaction with a decomposition product generated by exposure of the image-recording layer, and an on-press development type lithographic printing plate precursor having a support and an image-recording layer on the support in which the image-recording layer contains a compound represented by Formula 1C or Formula 2C and an electron-donating polymerization initiator. In Formula 1C and Formula 2C, R.sup.1C to R.sup.4C each independently represent a monovalent organic group, L.sup.1C and L.sup.2C each independently represent a divalent organic group, A.sup.C represents OH or NR.sup.5CR.sup.6C, and R.sup.5C and R.sup.6C each independently represent a monovalent organic group.

##STR00001##