A lithographic printing plate precursor has a substrate comprising a hydrophilic surface and two opposing edges; a radiation-sensitive imagable layer, and optionally, a protective layer disposed over that layer. The precursor has a shear droop at each opposing edge, each shear droop having a shear droop depth Y of 20-200 m and a shear droop width X of 500-2000 m. The precursor also has a hydrophilic coating band extending from each of the two opposing edges inwardly along the hydrophilic surface independently to provide a hydrophilic coating band width A of at least 1.5 times the shear droop width X. This hydrophilic coating band comprises amphoteric surfactant(s) in an amount greater than all other surfactants. Such individual precursors are obtained by cutting a continuous radiation-sensitive web into strips and such cutting creates the shear droop that can result in edge staining if the hydrophilic coating band is not present.

A negative type photosensitive resin composition includes a polymer compound which has, in a main chain thereof, a constitutional unit A represented by Formula A-1, a constitutional unit B that is at least one of constitutional units represented by Formulae B-1, B-2, B-3, B-4, B-5, B-6, or B-7, and a constitutional unit C containing an ethylenically unsaturated group; and a polymerization initiator.

A negative type planographic printing plate precursor includes an image recording layer containing the negative type photosensitive resin composition.

A method of preparing a planographic printing plate includes, in order, an exposure step of image-exposing the negative type planographic printing plate precursor; and a development step of performing development by removing a non-exposed portion of the exposed negative type planographic printing plate precursor using a developer.

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An on-press development type lithographic printing plate precursor includes a support and an image-recording layer on the support. The image-recording layer contains a polymerization initiator, an infrared absorber, a color forming substance precursor, and an auxiliary capable of donating an electron to the infrared absorber. A polymer having an ethylenically unsaturated group and a water-soluble monofunctional monomer are present on a surface of the support on an image-recording layer side, a layer in contact with the support on the image-recording layer side contains the polymer having an ethylenically unsaturated group and the water-soluble monofunctional monomer, or a layer in contact with the support on the image-recording layer side, other than the image-recording layer, contains the polymer having an ethylenically unsaturated group and the image-recording layer contains the water-soluble monofunctional monomer.

Flexographic printing members are prepared from a flexographic printing plate precursor consisting essentially of: backing film, water- or water-dispersible photosensitive layer, and cover sheet in contact with the photosensitive layer. The cover sheet is removed and a mask element is laminated directly in contact with the photosensitive layer. Exposure through the mask element provides exposed regions and non-exposed regions. The non-exposed regions are removed with an aqueous developer having: a) a C.sub.12-20 saturated or unsaturated fatty acid (or alkali metal salt) at 0.25-2.0 weight %, and at least 85 weight % of a C.sub.18 mono- or poly-unsaturated fatty acid (or alkali metal salt); b) an aminopolycarboxylic acid (or alkali metal salt) at 0.05-0.30 weight %; c) a buffer at 05-0.60 weight %; and d) water. The photosensitive layer has a controlled release of 5-500 g/cm using ASTM D-3330 Method D, between its front imaging surface and the mask element.

A method of making a lithographic printing plate includes the steps of a) image-wise exposing a lithographic printing plate precursor including a hydrophilic support and a coating containing a colorant precursor to form a lithographic image consisting of printing areas and non-printing areas, b) developing the plate precursor to remove the coating in the non-printing areas from the support, and c) drying the plate precursor, and d) subjecting the plate precursor to heat or radiation to induce a colour change of the coating in the printing areas, wherein before step b) the coating in the non-printing areas and the support are characterised by a CIE 1976 colour difference E.sub.1 which is 5.0 or less, and after step d) the CIE 1976 colour difference E.sub.2 between the coating in the printing areas and the non-printing areas is more than 6.8.

An on-press development type lithographic printing plate precursor, including an image-recording layer on a support, in which the image-recording layer contains an infrared absorber A, a borate compound B, an iodonium compound C, and a color forming substance precursor D, and a surface free energy of an outermost layer on an image-recording layer side is 115 mJ/m.sup.2 or less, and a method of preparing a lithographic printing plate, a lithographic printing method, and a laminate using the on-press development type lithographic printing plate precursor.

A photosensitive resin printing plate precursor is disclosed for relief printing, including a support, a photosensitive resin layer, and a cover film stacked in this order, wherein the photosensitive resin layer comprises a lower layer present on a support side and an upper layer present on a cover-film side, wherein the upper layer is a photosensitive resin layer that contains a water-soluble or water-dispersible resin (A) having a glass transition temperature measured by differential scanning calorimeter of 40 to 90 C., wherein the upper layer has a thickness of 3 to 30 micrometers, wherein the lower layer is a layer that contains a water-soluble or water-dispersible resin (B) having a glass transition temperature higher than the glass transition temperature of the water-soluble or water-dispersible resin (A) by 5 C. or more, and wherein the glass transition temperature of the resin (B) measured by differential scanning calorimeter is 95 to 135 C.

An actinic ray-sensitive or radiation-sensitive resin composition includes a resin (A) containing a repeating unit represented by General Formula (4) and a crosslinking agent (C) containing a polar group, in which the crosslinking agent (C) is a compound represented by General Formula (1) or a compound in which two to five structures represented by General Formula (1) are connected via a linking group or a single bond represented by L.sub.1 in General Formula (3). ##STR00001##

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 an infrared absorber, a polymerization initiator, a polymerizable compound, and a color-developing substance precursor, and in a case where the image-recording layer is exposed to an infrared laser having a wavelength of 830 nm at an energy density of 110 mJ/cm.sup.2, a loss of ethylenically unsaturated bonds in an exposed area in the image-recording layer is 10% to 40% of ethylenically unsaturated bonds in a non-exposed area in the image-recording layer, and a method for preparing a lithographic printing plate or a lithographic printing method using the on-press development type lithographic printing plate precursor.

An on-machine development type planographic printing plate precursor has a support and an image-recording layer on the support. The image-recording layer contains an initiator, an infrared absorber capable of donating electrons to the initiator, and a color-developing substance precursor. The image-recording layer can form an image by exposure to infrared laser, and in a case where the image-recording layer is exposed to an infrared laser with a wavelength of 830 nm at an energy density of 110 mJ/cm.sup.2, a brightness change L of the image-recording layer before and after the exposure is 3.0 or more. A method for preparing a planographic printing plate and a planographic printing method employ the on-machine development type planographic printing plate precursor.