Abstract: The invention provides a method for preparing a printing form from a photopolymerizable element. The photopolymerizable element includes a layer of a photopolymerizable composition containing an elastomeric block copolymer of polystyrene and polybutadiene having less than 15% by weight of 1,2-coupled bond segments in the polybutadiene block, an ethylenically unsaturated compound, and a photoinitiator. The method includes imagewise exposing the photopolymerizable element to actinic radiation in the presence of atmospheric oxygen; heating the element to a temperature sufficient to cause a portion of the layer to liquefy; and contacting an exterior surface of the photopolymerizable element with a development medium to allow at least a portion of the liquefied layer to be removed by the development medium.

Abstract: A method for making a positive-working lithographic printing plate includes the steps of: (1) providing a heat-sensitive printing plate precursor including on a support, having a hydrophilic surface or which is provided with a hydrophilic layer, a heat-sensitive coating; (2) image-wise exposing the precursor with heat and/or light; and (3) developing the exposed precursor with an aqueous alkaline developing solution including lithium ions at a concentration of at least 0.05% wt and a salt of an aliphatic carboxylic acid; wherein the molar ratio of the aliphatic carboxylic acid to the lithium ions is ?1.

Abstract: A lithographic printing plate precursor comprising an image-recording layer, said image-recording layer being photopolymerizable upon exposure to light having a wavelength of from 300 to 500 nm and containing a mixture of sensitizers.

Abstract: A method for treating a lithographic printing plate including the step of applying a liquid containing a surfactant to the plate, characterized in that the surfactant includes at least one hydrophilic segment including polyglycerol, and at least one hydrophobic segment selected from an optionally substituted alkylene group, an alkyl or aryl substituted poly(meth)acrylate, an optionally substituted polyester, polyether, polyurethane, polycarbosilane, polysiloxane, polystyrene and/or a polymer including a perfluoroalkyl group with the proviso that the liquid is not applied as a fountain solution.

Abstract: A lithographic printing plate precursor includes, in the following order: a support; an image-recording layer which is capable of forming an image by removing an unexposed area of the image-recording layer with at least one of printing ink and dampening water on a printing machine after exposure and contains an infrared absorbing dye, a polymerization initiator, a polymerizable compound and a binder polymer having an alkylene oxide group; and a protective layer containing a hydrophilic polymer which contains at least a repeating unit represented by the formula (1) as defined herein, a repeating unit represented by the formula (2) as defined herein, and a repeating unit represented by the formula (4) as defined herein, and in which a content of the repeating unit represented by the formula (4) is from 0.3 to 5.0% by mole based on total repeating units of the hydrophilic polymer.

Abstract: Lithographic printing plate precursors can have an imageable layer that includes a polymeric binder having an acid number of at least 30 mg KOH/g of polymer to and including 150 mg KOH/g of polymer, at least 3 weight % of recurring units derived from one or more N-alkoxymethyl (alkyl)acrylamides or alkoxymethyl (alkyl)acrylates, at least 2 weight % of recurring units having pendant 1H-tetrazole groups, and at least 10 weight % of recurring units having pendant cyano groups. The use of such polymeric binders provides good bakeability and chemical solvent resistance, especially for positive-working precursors.

Abstract: A negative-working lithographic printing plate precursor is designed for improved printout or contrast between exposed and non-exposed regions in its imageable layer. The imaged precursor can be developed on-press. The improvement in printout is achieved by using a combination of at least two infrared radiation absorbing cyanine dyes. At least one of these cyanine dyes comprises a methine chain substituent that comprises a group represented by Structure (I): wherein Q1 and Q2 are hydrogen atoms or the same or different monovalent substituents, or Q1 and Q2 together provide carbon or heteroatoms to form a substituted or unsubstituted unsaturated ring. At least one other infrared radiation absorbing cyanine dyes does not comprise a group represented by Structure (I).

Abstract: Negative-working imageable elements can be imaged and processed to provide lithographic printing plates. These imageable elements are sensitive to infrared radiation but are insensitive to “white” light and thus can be more easily handled under white light conditions. These properties are possible by incorporating a filter dye having a ?max of from about 300 to about 500 nm into the imageable layer of the imageable elements.

Abstract: A lithographic printing plate precursor includes: an aluminum support; an intermediate layer; and an image-recording layer, in this order, wherein at least one of the intermediate layer and the image-recording layer contains a compound having an amino group and a functional group capable of interacting with the aluminum support in a molecule.

Abstract: A lithographic printing plate precursor includes a support and a layer containing a polymer compound having at least one support-adsorbing group at a terminal of a main chain.

Abstract: A color contrast image in imaged lithographic printing precursors can be obtained by contacting the imaged precursor with a coloration solution containing a colorless form of a photochromic compound. Residual amounts of this compound attached to the oleophilic surface of the imaged precursor can be changed to its colored form when exposed to UV light. The coloration solution can be an alkaline or acidic developer or an alkaline or acidic solution used separately after development. The coloration solution can also be a gum solution.

Abstract: Disclosed is a method of making a lithographic printing plate which includes providing a lithographic printing plate precursor having a coating therein, image-wise exposing the coating, and developing the precursor. The coating includes (i) a contiguous photopolymerizable layer of a photopolymerizable composition or (ii) a contiguous intermediate layer with a photopolymerizable layer of a photopolymerizable composition thereon. The photopolymerizable composition includes a polymerizable compound, a polymerization initiator and a first polymer. The contiguous photopolymerizable layer or the contiguous intermediate layer also includes an adhesion promoting compound and a second polymer.

Abstract: An apparatus and method for improving the durability of an image on an imaging material, including increasing the press run length or a printing plate. The apparatus and method can involve the use of, as an example but not restricted to, an imaging device, a pre-bake oven, a processor, and a post-process treatment unit that employs infrared lamps adapted to irradiate the image.

Abstract: A heat-sensitive negative-working lithographic printing plate precursor comprising: a support having a hydrophilic surface or which is provided with a hydrophilic layer; and an image-recording layer comprising hydrophobic thermoplastic polymer particles, an infrared light absorbing dye and a dye; wherein said dye has a specified structure and a most bathochromic light absorption peak between 451 nm and 750 nm.

Abstract: A lithographic printing plate precursor comprises an imageable layer comprising a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to imaging infrared radiation, an infrared radiation absorbing dye comprising an infrared radiation absorbing cation and a counter anion, and a polymeric binder. The salt formed between the infrared radiation absorbing cation and a tetraphenyl borate has solubility in 2-methoxy propanol at 20° C. that is greater than or equal to 3.5 g/l. The use of these infrared radiation absorbing dyes in the imageable layers provides a reduced tendency of these dyes to crystallize in the presence of tetraaryl borate counter anions.

Abstract: A lithographic printing plate precursor comprises an imageable layer comprising a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to imaging infrared radiation, an infrared radiation absorbing dye that is defined by Structure (I) shown in the disclosure, which dyes comprise one or more ethylenically unsaturated polymerizable groups in an organic group that is attached to the methine chain. These infrared radiation absorbing dyes exhibit a reduced tendency to crystallize in the imageable layers in the presence of tetraaryl borate counter anions and therefore provide improved shelf life.

Abstract: A negative-working lithographic printing plate precursor is disclosed that can be developed on the press without going through a development processing step, and a method of lithographic printing is also disclosed that uses this negative-working lithographic printing plate precursor. Also disclosed are a negative-working lithographic printing plate precursor that can be developed by a water-soluble resin-containing aqueous solution and a method of lithographic printing that uses this negative-working lithographic printing plate precursor. A negative-working lithographic printing plate precursor is provided that exhibits an excellent fine line reproducibility in nonimage areas even when printing is performed using ultraviolet-curing ink (UV ink). Also provided is a negative-working lithographic printing plate precursor that exhibits an excellent combination of fine line reproducibility and printing durability and that resists the production of scum during on-press development.

Abstract: Disclosed is a photosensitive resin composition suitable for use in a transflective liquid crystal display (LCD). The photosensitive resin composition uses, as an alkali-soluble binder resin, a blend of two kinds of binder resins. The first binder resin has a weight average molecular weight greater than or equal to 1,000 but lower than 20,000 and contains no reactive group. The second binder resin has a weight average molecular weight greater than or equal to 20,000 but lower than 80,000 and contains reactive groups. The photosensitive resin composition has good adhesion to an underlying substrate while forming a high resolution fine pattern.

Abstract: Particular embodiments include method embodiments and apparatus embodiments. One method embodiment comprises: placing a printing plate on an imaging device; imaging the plate according to imaging data; and applying UV radiation using a plurality of UV emitting LEDs during the process of imaging of the printing plate. In one embodiment, the plate initially has ablatable material, and wherein the imaging includes ablating ablatable material on the plate according to the imaging data to form an ablated plate, and wherein the applying the UV radiation includes exposing the ablated plate to UV radiation to cure the plate. In one embodiment, the imaging device is an external drum imager that includes a drum that rotates during imaging.

Abstract: Provided is a lithographic printing plate precursor excellent in the printing durability, staining resistance and developability. The lithographic printing plate precursor comprises, on a support, an image recording layer, and an undercoat layer provided between the support and the image recording layer, the undercoat layer containing a polymer compound (D) composed of repeating units, the polymer compound (D) having, at the terminal of the principal chain thereof, a group having one or more groups selected from hydrophilic group and radical-polymerizable ethylenic unsaturated group, and each repeating unit having, as a side chain bound to the principal chain, one or more groups selected from support-adsorptive groups.

Abstract: A lithographic printing plate precursor includes, in the following order: a support; an image-recording layer which is capable of forming an image by removing an unexposed area by an automatic development processor in the presence of a developer having pH of from 2 to 14 after exposure and contains (A) a sensitizing dye, (B) a polymerization initiator, (C) a polymerizable compound and (D) a polymer which is insoluble in water and alkali-soluble; and a protective layer, and the protective layer contains (E) a hydrophilic polymer which has a repeating unit represented by the formula (1) as defined herein and a repeating unit represented by the formula (2) as defined herein and a sum of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) is at least 95% by mole based on total repeating units constituting the polymer.

Abstract: An aluminum-containing substrate can be provided for use in lithographic printing plate precursors. Before radiation-sensitive layers are applied, a grained and sulfuric acid anodized aluminum-containing support is treated with an alkaline or acidic pore-widening solution to provide its outer surface with columnar pores. The diameter of the columnar pores at their outermost surface is at least 90% of the average diameter of the columnar pores. Directly on this treated surface, a hydrophilic layer is applied, which hydrophilic layer contains a non-crosslinked hydrophilic polymer having carboxylic acid side chains.

Abstract: On-press developable, negative-working lithographic printing plate precursors have a sulfuric acid anodized aluminum-containing substrate in which the oxide layer pores have been widened using an acidic or alkaline treatment. Over the widened pores, a hydrophilic coating is applied, which coating comprises a non-crosslinked hydrophilic polymer having carboxylic acid side chains. This particular substrate provides improved adhesion and printing durability for on-press development and printing.

Abstract: A method for developing a printing plate precursor comprising the step of immersing the precursor in an aqueous alkaline developing solution comprising a (co)polymer comprising a monomeric unit which is represented by the following formula (I): wherein L is a linking group; R1, R2 and R3 independently represent hydrogen or an alkyl group; R4 represents an optionally substituted hydroxyaryl group; x=0 or 1; y=0 or 1 and when y=0 then x=1 and L is further bound to C* to form a cyclic structure.

Abstract: Lithographic printing plate precursors have been designed so that they can be stored, shipped, and used in stacks without interleaf paper between individual precursors. This is achieved by incorporating polymeric particles having an average diameter of from about 3 to about 20 ?m into the outermost precursor layer such as an imagable layer or topcoat. The polymeric particles comprise a core of a crosslinked polymer and have grafted hydrophilic polymeric surface groups that are grafted onto the particle surfaces by polymerizing hydrophilic monomers in the presence of the crosslinked polymeric particles. The lithographic printing plates can be either negative- or positive-working elements.

Abstract: A method of preparing a lithographic printing plate in which no pre-heat step is used comprising the steps of:—providing a lithographic printing plate precursor comprising a support and a photopolymerizable image-recording layer, the image-recording layer comprising a monomer and a binder;—image-wise exposing the precursor in an exposure unit;—off press developing the exposed precursor with an aqueous solution in a processing unit; characterized in that the ratio of the total amount of monomer to the total amount of binder is at least 1 and the time lapse between exposing an image-area of the precursor and contacting the image-area with the aqueous solution is at least 1 minute.

Abstract: A heat-sensitive negative-working lithographic printing plate precursor includes on a grained and anodized aluminum support a coating including hydrophobic thermoplastic polymer particles, a hydrophilic binder, and an organic compound, wherein the organic compound includes at least one phosphonic acid group or at least one phosphoric acid group or a salt thereof.

Abstract: Negative-working imageable elements have a hydrophilic substrate and a single thermally-sensitive imageable layer. This layer can include an infrared radiation absorbing compound and polymeric particles that coalesce upon thermal imaging. These coalesceable polymeric particles comprise a thermoplastic polymer and a colorant to provide improved visible contrast between exposed and non-exposed regions in the imaged element, such as lithographic printing plates.

Abstract: A method of on-press development of a lithographic printing plate having an imaged photosensitive (PS) coating by (a) applying an emulsive film of press ink and fountain onto the entire PS coating; (b) transferring all nonimage areas of the inked PS coating and all of the ink film on the nonimage areas of the PS coating from the plate to a blanket roll while the image areas of the PS coating remain on the substrate, wherein the nonimage areas are transferred to the blanket roll in particulate form without dissolution or dispersion in any ink or fountain; and (c) contacting the blanket roll with a paper leader to further transfer all the ink, fountain water, and particles of nonimage PS coating that were transferred to the blanket roll, from the blanket roll to the paper leader.

Abstract: A lithographic printing plate precursor includes an image-recording layer and a support, and the image-recording layer contains: (A) at least one compound selected from compounds represented by the following formulae (1) and (2); and (B) an infrared absorbing agent: wherein R1 and R2 each represents Ra—SO3—, Ra—CO2— or Ra—OCO2—, Ra represents a monovalent organic group, R3 to R12 each represents a hydrogen atom or a monovalent substituent, or adjacent two of R3 to R12 may be combined with each other to form a ring, X1, Y1 and Z1 and X2, Y2 and Z2 each represents an atomic group necessary to form a thiazole ring, an oxazole ring, an imidazole ring, a triazole ring or a 3H-indole ring, provided that one nitrogen atom of the imidazole ring is connected to a hydrogen atom or a monovalent organic group.

Abstract: A lithographic processing solution has a pH of less than 12 and comprises at least 0.001 and up to and including 1 weight % of a water-soluble or water-dispersible, non-IR-sensitive compound that has a heterocyclic moiety with a quaternary nitrogen in the 1-position of the heterocyclic ring, and has one or more electron donating substituents attached to the heterocyclic ring, at least one of which electron donating substituents is attached in the 2-position. This processing solution can be used to develop both single-layer and multi-layer positive-working lithographic printing plate precursors that have been imaged using infrared radiation.

Abstract: A lithographic printing plate precursor includes: a support having a surface, a contact angle of water droplet in air on which is 70° or more; and a photosensitive layer, wherein the support has, on a surface of the support, a compound having a functional group X, the functional group X is a functional group capable of forming a chemical bond with a compound having a functional group Y which can interact with the functional group X, when the functional group X is brought into contact with the compound having a functional group Y, to adsorb the compound having a functional group Y on the surface of the support so as to decrease the contact angle of water droplet in air on the surface of the support to 30° or less.

Abstract: Method for producing an imaged lithographic printing plate comprising the step of developing an imagewise exposed negative working precursor with a developer comprising an alkylene oxide derivative of formula (A), wherein R1 is a linear or branched C1 to C6 alkyl group or H, (n+m) is an integer from 2 to 30, and R2 R3 R4 and R5 are each independently selected from H, methyl and ethyl, with the proviso that at least one of R2 and R3 is not H, and with the further proviso that at least one of R4 and R5 is not H.

Abstract: To provide a developer for processing of a lithographic printing plate precursor, containing a non-reducing sugar having bonded therein two or more monosaccharides and having a pH of 6 to 14 and thereby provide a developer having a pH stable to aging and an excellent film-forming property, a method for manufacturing a lithographic printing plate, where a lithographic printing plate excellent in developability and dispersibility of development scum and kept from staining of the non-image area can be manufactured even by simple processing of one solution and one step requiring no water washing step, a developer used therefor, and a printing method of performing printing by using the manufacturing method of a lithographic printing plate.

Abstract: Negative-working imageable elements such as lithographic printing plate precursors, include a free-radically polymerizable component, an initiator composition that is capable of generating free radicals sufficient to initiate polymerization of the free-radically polymerizable component upon exposure to imaging radiation in the presence of a radiation absorbing compound, a radiation absorbing compound, an aerobic free radical inhibitor, optionally a polymeric binder that is not a free radically polymerizable component, and an anaerobic free radical inhibitor. The molar ratio of the anaerobic free radical inhibitor to the aerobic free radical inhibitor is at least 1:1. This combination of inhibitors provides increased shelf life and good latent image stability particularly when the element includes a polymeric topcoat layer that functions as an oxygen barrier.

Abstract: A lithographic apparatus, includes a support structure configured to hold a patterning device, the patterning device configured to impart a beam of radiation with a pattern in its cross-section; a substrate table configured to hold a substrate; a projection system configured to project the patterned beam onto a target portion of the substrate; a liquid supply system configured to provide liquid to a space between the projection system and the substrate table; a sensor configured to measure an exposure parameter using a measuring beam projected through the liquid; and a correction system configured to determine an offset based on a change of a physical property impacting a measurement made using the measuring beam to at least partly correct the measured exposure parameter.

Abstract: To provide a coloring photosensitive composition and a lithographic printing plate precursor, ensuring that coloring stability after exposure by infrared laser exposure is good and high coloring is obtained even when exposed after the elapse of time. These can be a coloring photosensitive composition containing a microgel encapsulating (A) a polymer having a glass transition temperature of 50° C. or more, (B) a photoinitiator, and (C) an infrared absorbing dye, and a lithographic printing plate precursor having an image-recording layer containing the composition.

Abstract: By a method of preparing a lithographic printing plate having exposing a lithographic printing plate precursor including a photosensitive layer containing (A) a polymerization initiator, (B) a polymerizable compound, (C) a sensitizing dye and (D) a binder polymer and a protective layer in this order on a hydrophilic support with laser and then removing the protective layer and an unexposed area of the photosensitive layer in the presence of a developer, in which the developer is a developer which has pH of from 2 to less than 10 and contains an amphoteric surfactant and a nonionic surfactant having an alkylene oxide chain, a simple processing of one solution and one step which does not require a water washing step becomes possible, excellent development property is achieved and a lithographic printing plate which has good printing durability and does not cause printing stain can be provided.

Abstract: An inorganic electron beam sensitive oxide layer is formed on a carbon based material layer or an underlying layer. The inorganic electron beam sensitive oxide layer is exposed with an electron beam and developed to form patterned oxide regions. An ultraviolet sensitive photoresist layer is applied over the patterned oxide regions and exposed surfaces of the carbon based material layer, and subsequently exposed with an ultraviolet radiation and developed. The combined pattern of the patterned ultraviolet sensitive photoresist and the patterned oxide regions is transferred into the carbon based material layer, and subsequently into the underlying layer to form trenches. The carbon based material layer serves as a robust mask for performing additional pattern transfer into the underlying layer, and may be easily stripped afterwards. The patterned ultraviolet sensitive photoresist, the patterned oxide regions, and the patterned carbon based material layer are subsequently removed.

Abstract: A negative-working lithographic printing plate precursor have an outermost imageable layer that includes an oxygen scavenger and shelf-life stabilizer that is represented by either Structure (I) or Structure (II) below: HOOC—Ar—N(R1)(R2)??(I) HOOC—R5—N(R6)(R7)??(II) wherein Ar is a phenylene or naphthylene group, R1 and R2 are independently alkyl, alkenyl, alkynyl, phenyl, phenoxy, —R5OH, —CH2—C(?O)—R3, or —CH2—C(?O)O—R4 groups, R3 is hydrogen or an alkyl or phenyl group, R4 is an alkyl or phenyl group, R5 is an alkylene group, R6 and R7 are independently hydrogen or an alkyl, —R5OH, —R5C(?O)—R8, or —R5C(?O)OR9 group, R8 is hydrogen or an alkyl group, and R9 is an alkyl group, provided that the oxygen scavenger has no more than one carboxyl group.

Abstract: Imageable elements can be imaged and then processed using a solution containing core-shell particles that are designed to complex with non-coalesced particles in the non-exposed regions of imaged element. A separate development step is not needed, but the non-coalesced particles and complexed core-shell particles can be removed from the resulting printing plate before using the resulting lithographic printing plate for printing.

Abstract: A multi-layer, positive-working lithographic printing plate precursor can be imaged with infrared radiation and processed in a single step using a single processing solution that has a pH greater than 6 and up to about 11. This single processing solution both develops the imaged precursor and provides a protective coating that need not be rinsed off before lithographic printing.

Abstract: Negative-working imageable element can be used to provide lithographic printing plates. The imageable element has a suitable radiation-sensitive imageable layer and a water-soluble overcoat disposed on the imageable layer. This overcoat comprises at least one poly(vinyl alcohol) having a saponification degree of at least 90%, an alkoxylation product of an alkanol, and either a 2-sulfonato succinic acid dialkylester or an alkoxylation product of a 1,4-butanediol.

Abstract: A method includes removing the previously imaged area (120) from the flexographic plate (104) to create an opening in the flexographic plate; providing a portion (108) from a flexographic plate built from similar material of the previously imaged flexographic plate; adding adhesive material (116) to the portion or to the opening or to the portion and to the opening; placing the opening within the portion; curing the adhesive material to permanently fix the portion to the flexographic plate; polishing the top (508) of the portion to match to the top surface (504) of the flexographic plate; and imaging the portion.

Abstract: A processing method of a lithographic printing plate precursor includes: exposing imagewise a lithographic printing plate precursor comprising a support on a surface of which at least one of: a hydrophilizing treatment; and an undercoat layer has been provided and an image-recording layer, to cure an exposed area of the image-recording layer; and undergoing developing processing with an aqueous solution having pH of from 2 to 10, wherein the aqueous solution comprises an amphoteric surfactant and an anionic surfactant selected from an anionic surfactant having an aliphatic chain and a total number of carbon atoms included in the aliphatic chain of 6 or more and an anionic surfactant having an aromatic ring and a total number of carbon atoms of 12 or more, and a content of the anionic surfactant is from 0.1 to 3.3% by weight of the aqueous solution.

Abstract: A heat-sensitive lithographic printing plate precursor comprising on a grained and anodized aluminum support a compound which is capable of converting form a hydrophobic state to a hydrophilic state or vice versa upon exposure to heat, and is represented by the following formula: A-(L)n-B wherein L represents a linking group, n represents 0 or 1 and B represents a thermo-labile group; characterized in that the compound further comprises the group A which is a functional group capable of interacting with the surface of a grained and anodized aluminum support and is selected from the list consisting of a halosilanyl group, an alkoxysilanyl group, a phosphonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a salicylic acid group or a salt thereof, a boronic acid group or an ester or a salt thereof, an optionally substituted di or tri-hydroxyaryl group, an optionally substituted salicaldoxime group, an optionally substituted salicaldimine group, an optionally substituted hydroxyheteroa

Abstract: A lithographic printing plate precursor includes: an aluminum support; an intermediate layer; and an image-recording layer, in this order, wherein at least one of the intermediate layer and the image-recording layer contains a compound having an amino group and a functional group capable of interacting with the aluminum support in a molecule.

Abstract: A plate carries a solvent-soluble, radiation-polymerizable, oleophilic resin coating non-ionically adhered on a hydrophilic substrate, which can be imagewise exposed to polymerizing radiation and then directly processed by the application of disruptive mechanical forces such as compression or tension to remove the unimaged areas as undissolved particles, using pressurized water and brushing pre-press, or the tack of the ink on-press.

Abstract: A lithographic printing plate precursor is provided that includes, above a support, a photosensitive layer including (i) a binder polymer, (ii) an ethylenically unsaturated compound, and (iii) a polymerization initiator, the ethylenically unsaturated compound (ii) including a compound represented by Formula (1) below. (In Formula (1), L denotes an (m+n)-valent linking group, the Ds independently denote a group selected from the group consisting of groups represented by Formulae (A) to (D) below, the Rs independently denote a monovalent substituent, m denotes an integer of 1 to 20, and n denotes an integer of 2 to 20.) (In Formulae (A) to (D), X, Y, and Z independently denote an oxygen atom, a sulfur atom, or NR17, R4 to R14 and R17 independently denote a hydrogen atom or a monovalent substituent, R15 denotes a hydrogen atom or a methyl group, R16 denotes a monovalent substituent, and k denotes an integer of 0 to 4.

Abstract: A heat-sensitive positive-working lithographic printing plate precursor comprising (1) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (2) a heat-sensitive coating, comprising an underlayer on said support and thereon an upperlayer, an IR absorbing agent in at least one of said underlayer and upperlayer, a phenolic resin in said upperlayer, and a first polymer in said underlayer, characterized in that said first polymer is an alkaline soluble polymer comprising a first sulfonamide containing monomeric unit having a specified structure according to formula I or formula II and a second amide containing monomeric unit having a specified structure according to formula III. The printing plates show an improved chemical resistance of the coating and a reduced undercutting of the image forming parts of the coating.