# US 2010/0167209 A1 · Method of using mask film to form relief images > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0167209 A1 - Document ID: US20100167209A1 - Status: Published application - Kind: A1 - Application number: 12/722,572 - Filed: 2010-03-12 - Published: 2010-07-01 - Earliest claimed: 2007-06-05 - Assignees: Eastman Kodak Company - Inventors: Gregory L. Zwadlo; David E. Brown; Elsie A. Fohrenkamm; A. Peter Stolt - Web page: https://patentgrep.com/patent/US20100167209A1 ## CPC - G03F 1/68: Preparation processes not covered by groups G03F1/20 - G03F1/50 - B41M 5/40: characterised by the base {backcoat}, intermediate, or covering layers, {e.g. for thermal transfer dye-donor or dye-receiver sheets}; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography {(macromolecular ink- or dye-receptive coatings B41M5/52)} - G03F 7/2014: {Contact or film exposure of light sensitive plates such as lithographic plates or circuit boards, e.g. in a vacuum frame} - G03F 7/202: {Masking pattern being obtained by thermal means, e.g. laser ablation} - B41C 1/05: Heat-generating engraving heads, e.g. laser beam, electron beam - Y10S 430/145: Infrared - Y10T 428/24942: including components having same physical characteristic in differing degree - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - B41M: PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING, (correction of typographical errors B41J; processes for applying transfer pictures or the like B44C1/16; fluid media for correction of typographical errors by coating C09D10/00; printing textiles D06P) - B41C: PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES (photomechanical processes for producing printing surfaces G03F; photoelectrical processes for producing printing surfaces G03G) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A mask-forming film has a transparent layer between the imageable layer and the carrier sheet, which transparent layer has a refractive index that is lower (by at least 0.04) than that of the carrier sheet or any immediately adjacent layer between it and the carrier sheet. This lower refractive index layer modifies the path of incident radiation during mask image transfer so as to provide steeper shoulder angles in the relief image solid areas. This mask film is used to form a relief image such as in a flexographic printing plate. ## Claims ### Claim 1 A method of making a relief image, the method comprising: A) forming a mask image by forming exposed and non-exposed regions in an imaged film, which film prior to imaging, comprises: a transparent carrier sheet having thereon at least one non-silver halide thermally sensitive imageable layer and a colorant disposed in the imageable layer, an infrared radiation absorbing compound dispersed in a polymeric binder, and a transparent layer disposed between the carrier sheet and the imageable layer, which transparent layer has a refractive index lower than the refractive index of the carrier sheet or the refractive index of any optional immediately adjacent layer between the carrier sheet and the transparent layer, B) transferring the mask image in the imaged film to a radiation-sensitive element while there is complete optical contact between the mask image and the radiation-sensitive element, C) exposing the radiation-sensitive element to curing radiation through the mask image to form an imaged element, wherein the mask image is opaque to the curing radiation, and D) developing the imaged element to form a relief image. ### Claim 2 (depends on 1) The method of claim 1 wherein the imaged film is removed from optical contact with the exposed radiation-sensitive element between steps C and D. ### Claim 3 (depends on 1) The method of claim 1 wherein the carrier sheet and transparent layer are removed from the imaged film between steps C and D. ### Claim 4 (depends on 1) The method of claim 1 wherein the radiation-sensitive element is a UV-sensitive element that is exposed to UV radiation through the mask image to form an imaged element, wherein the mask image is opaque to UV radiation. ### Claim 5 (depends on 1) The method of claim 1 wherein the radiation-sensitive element is a flexographic printing plate precursor and the imaged element is a flexographic printing plate. ### Claim 6 (depends on 1) The method of claim 1 wherein the relief image formed in the radiation-sensitive element has an average shoulder angle of at least 50°. ### Claim 7 (depends on 1) The method of claim 1 wherein the transferring step B is carried out by lamination. ### Claim 8 (depends on 1) The method of claim 1 wherein the transferring step B is carried out by applying a radiation-sensitive layer while in liquid form, to the imaged film, and then forming the radiation-sensitive element. ### Claim 9 (depends on 1) The method of claim 1 wherein the transparent layer has a refractive index of at least 0.04 lower than the refractive index of the carrier sheet. ### Claim 10 (depends on 1) The method of claim 1 wherein the transparent layer comprises a fluoroelastomer and optionally an adhesion promoter. ### Claim 11 (depends on 1) The method of claim 1 wherein the transparent layer has a thickness of from about 0.25 to about 10 μm. ### Claim 12 (depends on 1) The method of claim 1 wherein the film further comprises an intermediate layer between the imageable layer and the transparent layer, which intermediate layer has a thickness of from about 0.1 to about 10 μm. ### Claim 13 (depends on 12) The method of claim 12 wherein the intermediate layer comprises a poly(vinyl alcohol), poly(vinyl butyral), a cellulosic polymer, or hydrolyzed styrene maleic anhydride polymer. ### Claim 14 (depends on 1) The method of claim 1 wherein the film further comprises a barrier layer disposed between the imageable layer and the carrier sheet, the barrier layer comprising a heat-combustible polymer binder and an infrared radiation absorbing compound. ### Claim 15 (depends on 1) The method of claim 1 wherein the colorant in the imageable layer is a UV-absorbing dye. ### Claim 16 (depends on 1) The method of claim 1 wherein the film comprises a carrier sheet having thereon, in order: a) a transparent layer comprising a fluoroelastomer and having a thickness of from about 0.25 to about 10 μm, the transparent layer optionally including an adhesion promoter, and the transparent layer having a refractive index of at least 0.04 lower than the refractive index of the carrier sheet, b) an intermediate layer comprising a poly(vinyl alcohol), cellulosic polymer, poly(vinyl butyral), hydrolyzed styrene maleic anhydride polymer, or a thermally resistant polymer, and having a thickness of from about 0.1 to about 10 μm, the intermediate layer optionally including a crosslinking agent, coating aid, surfactant, or release-enhancing agent, c) a barrier layer comprising a poly(cyanoacrylate) or nitrocellulose, and an infrared radiation absorbing dye, and optionally metal oxide particles or crosslinking agents, d) a imageable layer comprising an infrared radiation absorbing dye and a UV-absorbing colorant dispersed in a polyurethane, poly(vinyl butyral), acrylamide polymer, nitrocellulose, or polyacetal binder, and e) an overcoat comprising a methacrylic acid copolymer and fluoropolymer particles. ### Claim 17 (depends on 16) The method of claim 16 wherein the transparent layer has a refractive index at least 0.08 lower than the refractive index of the carrier sheet. ### Claim 18 (depends on 16) The method of claim 16 wherein the barrier layer includes an infrared radiation absorbing compound. ### Claim 19 (depends on 16) The method of claim 16 wherein the infrared radiation absorbing compound in the imageable layer is an IR dye. ### Claim 20 (depends on 16) The method of claim 16 wherein the carrier sheet is a polyester, fluorine polyester polymer, polyethylene polypropylene, polybutadiene, polycarbonate, polyacrylate, polyvinyl chloride or copolymer thereof, or hydrolyzed or non-hydrolyzed cellulose acetate, and is from about 20 to about 200 μm thick, and optionally includes an adhesion promoter. ### Claim 21 (depends on 16) The method of claim 16 wherein the transparent layer has a thickness of from about 0.4 to about 10 μm. ### Claim 22 (depends on 16) The method of claim 16 wherein the intermediate layer further comprises an adhesion promoter.