# US 8,771,926 B2 · Slip film for relief image printing element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,926 B2 - Document ID: US8771926B2 - Status: Granted - Kind: B2 - Application number: 13/169,296 - Filed: 2011-06-27 - Published: 2012-12-27 - Granted: 2014-07-08 - Earliest claimed: 2011-06-27 - Applicants: Kyle P. Baldwin; Miguel A. Barboza; Laurie A. Bryant; Jessica A. Elwell - Inventors: Kyle P. Baldwin; Miguel A. Barboza; Laurie A. Bryant; Jessica A. Elwell - Web page: https://patentgrep.com/patent/US8771926B2 ## CPC - G03F 7/092: {characterised by backside coating or layers, by lubricating-slip layers or means, by oxygen barrier layers or by stripping-release layers or means} - C08F 126/10: N-Vinyl-pyrrolidone - C08L 25/06: Polystyrene - C09D 125/06: Polystyrene - 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) - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) ## Abstract A method of preparing a photosensitive printing blank, the method comprising the steps of: a) coating a slip film onto a coversheet and drying the slip film; and depositing at least one layer of photosensitive material on top of the slip film coated coversheet and laminating a substrate layer to the exposed surface of the photosensitive material. The slip film comprises: i) a polymer selected from the group consisting of polystyrene and polyvinylpyrrolidone; ii) optionally, an additive. The slip film at least substantially eliminates the formation of hot spots during an analog plate making process. ## Claims ### Claim 1 A method of preparing a photosensitive printing blank, the method comprising the steps of: a) coating a slip film onto a coversheet and drying the slip film; and b) depositing at least one layer of photosensitive material on top of the dried slip film coated coversheet and laminating a substrate layer to an exposed face of the at least one layer of photosensitive material; wherein the slip film comprises: i) a polymer selected from the group consisting of polystyrene and polyvinylpyrrolidone; and ii) 0.1 to 5.0 percent by weight of an additive, where the additive is selected from the group consisting of ethylene glycol, propylene glycol, mineral oils, styrene-butadiene oils, butadiene oils, and copolymers of acetonitriles; wherein prior to drying, the slip film also comprises a solvent selected from the group consisting of toluene, acetone, primary alcohols, methylethyl ketone, 2-propanol, and combinations of one or more of the foregoing. ### Claim 2 (depends on 1) The method according to claim 1, wherein the concentration of the polymer in the slip film, prior to drying, is between about 6 to about 30 percent by weight. ### Claim 3 (depends on 2) The method according to claim 2, wherein the concentration of the polymer in the slip film, prior to drying, is between about 6 to about 11 percent by weight. ### Claim 4 (depends on 1) The method according to claim 1, wherein the concentration of the solvent in the slip film prior to drying is between about 65 to about 95 percent by weight. ### Claim 5 (depends on 4) The method according to claim 4, wherein the concentration of the solvent in the slip film prior to drying is between about 85 to about 95 percent by weight. ### Claim 6 (depends on 1) The method according to claim 1, wherein the concentration of the additive in the slip film, prior to drying, is between about 0.5 to about 3.5 percent by weight. ### Claim 7 (depends on 1) The method according to claim 1, wherein the thickness of the slip film is between about 1.0 and about 15.0 grams per square meter. ### Claim 8 (depends on 7) The method according to claim 7, wherein the thickness of the slip film is between about 2.0 and about 5.0 grams per square meter. ### Claim 9 (depends on 8) The method according to claim 8, wherein the thickness of the slip film is about 2.5 grams per square meter. ### Claim 10 (depends on 1) The method according to claim 1, wherein the slip film does not include a polyamide. ### Claim 11 (depends on 1) The method according to claim 1, wherein the slip film comprises polystyrene as the polymer. ### Claim 12 (depends on 11) The method according to claim 11, wherein the additive is present in the slip film and comprises a co-polymer of acetonitrile. ### Claim 13 (depends on 1) The method according to claim 1, wherein the slip film comprises polyvinylpyrrolidone as the polymer. ### Claim 14 (depends on 13) The method according to claim 13, wherein the additive is present in the slip film and comprises a co-polymer of acetonitrile. ### Claim 15 (depends on 1) The method according to claim 1, further comprising the steps of: a) removing the coversheet from the slip film and the at least one layer of photosensitive material; b) placing a negative on top of the slip film; c) exposing the at least one layer of photosensitive material to actinic radiation through the negative to selectively crosslink and cure the at least one layer of photosensitive material and produce a relief image printing element; wherein the presence of the slip film at least substantially eliminates the formation of hot spots in the relief image printing element. ### Claim 16 (depends on 1) The method according to claim 1, wherein the solvent comprises toluene. ### Claim 17 (depends on 1) The method according to claim 1, wherein the solvent comprises acetone.