# US 8,771,918 B2 · Lithographic printing plate precursor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,918 B2 - Document ID: US8771918B2 - Status: Granted - Kind: B2 - Application number: 13/378,025 - Filed: 2010-06-03 - Published: 2012-04-12 - Granted: 2014-07-08 - Earliest claimed: 2009-06-18 - Assignees: Agfa Graphics NV - Applicants: Xavier André; Philippe Moriamé; Hubertus Van Aert - Inventors: Xavier André; Philippe Moriamé; Hubertus Van Aert - Web page: https://patentgrep.com/patent/US8771918B2 ## CPC - B41C 1/1008: {by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials} - B41C 1/1016: {characterised by structural details, e.g. protective layers, backcoat layers or several imaging layers} - B41C 2201/02: Cover layers; Protective layers - B41C 2201/14: characterised by macromolecular organic compounds, e.g. binder, adhesives - B41C 2210/02: Positive working, i.e. the exposed (imaged) areas are removed - B41C 2210/06: Developable by an alkaline solution - B41C 2210/22: characterised by organic non-macromolecular additives, e.g. dyes, UV-absorbers, plasticisers - B41C 2210/24: characterised by a macromolecular compound or binder obtained by reactions involving carbon-to-carbon unsaturated bonds, e.g. acrylics, vinyl polymers - B41C 2210/262: Phenolic condensation polymers, e.g. novolacs, resols - B41C: PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES (photomechanical processes for producing printing surfaces G03F; photoelectrical processes for producing printing surfaces G03G) ## Abstract A positive-working lithographic printing plate precursor is disclosed which comprises on a support having a hydrophilic surface or which is provided with a hydrophilic layer a heat and/or light-sensitive coating including an infrared absorbing agent and a compound including a benzoxazine group. ## Claims ### Claim 1 A positive-working lithographic printing plate precursor which comprises on a support having a hydrophilic surface or which is provided with a hydrophilic layer, a heat and/or light-sensitive coating including an infrared absorbing agent and an alkali soluble resin including a benzoxazine group, wherein the alkali soluble resin comprises a monomeric unit derived from the monomer according to the following structure (V): wherein R3 to R6 represent hydrogen, a halogen, an optionally substituted straight, branched or cyclic alkyl, aralkyl, hetero-aralkyl, (di)alkylamine, aryl, heteroaryl group, or a structural moiety comprising an ethylenically unsaturated polymerizable group and/or combinations thereof; each of adjacent R3 to R5 may represent the necessary atoms to form one or more cyclic structure(s); and with the proviso that at least one of R3 to R6 represents or comprises a structural moiety including an ethylenically unsaturated polymerizable group. ### Claim 2 (depends on 1) A printing plate precursor according to claim 1 wherein the ethylenically unsaturated polymerizable group is represented by: wherein X represents oxygen, sulfur or an optionally substituted nitrogen; m represents 0, 1 or an integer greater than 1; and R7 represents hydrogen, an alkyl, an alkoxy, a carboxylic acid or an ester group; and * represents the bond whereby the ethylenically unsaturated polymerizable group is attached to structure (V). ### Claim 3 (depends on 1) A printing plate precursor according to claim 1 wherein the alkali soluble resin comprises 0.5 to 10 mol % of the monomeric unit according to structure (V). ### Claim 4 (depends on 1) A printing plate precursor according to claim 1 wherein the alkali soluble resin further comprises a monomeric unit selected from an acrylate, a methacrylate, styrene, an acrylamide, a methacrylamide or a maleimide, or a monomeric unit including a sulphonamide group. ### Claim 5 (depends on 1) A printing plate precursor according to claim 1 wherein the alkali soluble resin further comprises a monomeric unit including a sulphonamide group represented by —NRj—SO2—, —SO2—NRk— wherein Rj and Rk each independently represent hydrogen, an optionally substituted alkyl, alkanoyl, alkenyl, alkynyl, cycloalkyl, heterocyclic, aryl, heteroaryl, aralkyl, heteroaralkyl group or combinations thereof. ### Claim 6 (depends on 5) A printing plate precursor according to claim 5 wherein the alkali soluble resin comprises 50 to 80 mol % of the monomeric unit including a sulphonamide group. ### Claim 7 (depends on 2) A printing plate precursor according to claim 2 wherein the alkali soluble resin comprises 0.5 to 10 mol % of the monomeric unit according to structure (V). ### Claim 8 (depends on 2) A printing plate precursor according to claim 2 wherein the alkali soluble resin further comprises a monomeric unit selected from an acrylate, a methacrylate, styrene, an acrylamide, a methacrylamide or a maleimide, or a monomeric unit including a sulphonamide group. ### Claim 9 (depends on 2) A printing plate precursor according to claim 2 wherein the alkali soluble resin further comprises a monomeric unit including a sulphonamide group represented by —NRj—SO2—, —SO2—NRk— wherein Rj and Rk each independently represent hydrogen, an optionally substituted alkyl, alkanoyl, alkenyl, alkynyl, cycloalkyl, heterocyclic, aryl, heteroaryl, aralkyl, heteroaralkyl group or combinations thereof. ### Claim 10 (depends on 1) A method for making a positive-working lithographic printing plate comprising the steps of: imagewise exposing a heat-sensitive lithographic printing plate precursor according to claim 1 to heat and/or infrared light; developing said imagewise exposed precursor with an aqueous alkaline developer so that the exposed areas are dissolved; and baking the obtained plate. ### Claim 11 A positive-working lithographic printing plate precursor which comprises on a support having a hydrophilic surface or which is provided with a hydrophilic layer, a heat and/or light-sensitive coating including an infrared absorbing agent and a compound including a benzoxazine group represented by one of the following structures: wherein Q and Q′ independently represent an optionally substituted alkylidene or hetero-alkylidene group, an optionally substituted nitrogen, an oxygen, a sulphone, a sulphoxide, a carbonyl, a thioether, a thiol or a phosphine oxide group; R10 represents hydrogen or an optionally substituted alkyl, alicyclic alkyl, aralkyl, aryl or heteroaryl group; R11, R12 and R13 independently represent hydrogen, a halogen or an optionally substituted alkyl, alicyclic alkyl, aralkyl, aryl or heteroaryl group; and n and n′ independently represent an integer comprised between 1 and 4, wherein the compound including a benzoxazine group is present in the coating in an amount comprised between 0.01 g/m2 to 1 g/m2. ### Claim 12 (depends on 11) A method for making a positive-working lithographic printing plate comprising the steps of: imagewise exposing a heat-sensitive lithographic printing plate precursor according to claim 11 to heat and/or infrared light; developing said imagewise exposed precursor with an aqueous alkaline developer so that the exposed areas are dissolved; and baking the obtained plate.