# US 11,898,047 B2 · Ink set and ink jet method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,898,047 B2 - Document ID: US11898047B2 - Status: Granted - Kind: B2 - Application number: 17/458,826 - Filed: 2021-08-27 - Published: 2022-03-03 - Granted: 2024-02-13 - Earliest claimed: 2020-08-28 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Kyohei Tanaka; Yuko Hishida; Midori Sekine - Web page: https://patentgrep.com/patent/US11898047B2 ## CPC - C09D 11/40: Ink-sets specially adapted for multi-colour inkjet printing - B41J 2/21: for multi-colour printing - B41J 2/2114: {Ejecting specialized liquids, e.g. transparent or processing liquids (B41J2/211 takes precedence)} - B41J 11/002: {Curing or drying the ink on the copy materials, e.g. by heating or irradiating} - B41M 5/0023: {Digital printing methods characterised by the inks used (inks per se C09D11/00)} - C09D 11/037: characterised by the pigment - C09D 11/101: Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing - C09D 11/107: from unsaturated acids or derivatives thereof - C09D 11/322: Pigment inks - B41M 3/008: {Sequential or multiple printing, e.g. on previously printed background; Mirror printing; Recto-verso printing; using a combination of different printing techniques; Printing of patterns visible in reflection and by transparency; by superposing printed artifacts} - B41M 7/0081: {using electromagnetic radiation or waves, e.g. ultraviolet radiation, electron beams} - 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) - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - 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) ## Abstract An ink set of a radiation-curable ink jet composition containing a polymerizable compound, wherein the ink set includes a color ink and a clear ink as the radiation-curable ink jet composition, the polymerizable compound contained in the clear ink contains at least one of Polymerizable monomer A1 and Polymerizable oligomer A2, Polymerizable monomer A1 having a volume of 0.26 nm3 or more and an area in the direction of the height relative to a long side of 0.25 nm2 or more that are defined by using the van-der-Waals radius, and a total content of Polymerizable monomer A1 and Polymerizable oligomer A2 contained in the clear ink is 80% by mass or more relative to a total amount of the polymerizable compound. ## Claims ### Claim 1 An ink set of a radiation-curable ink jet composition containing a polymerizable compound, wherein the ink set includes a color ink and a clear ink as the radiation-curable ink jet composition, the polymerizable compound contained in the clear ink contains at least one of Polymerizable monomer A1 and Polymerizable oligomer A2, the Polymerizable monomer A1 having a volume of 0.26 nm3 or more and 0.60 nm3 or less, and an area in the direction of the height relative to a long side of 0.25 nm2 or more and 0.50 nm2 or less that are defined by using the van-der-Waals radius, and a total content of the Polymerizable monomer A1 and the Polymerizable oligomer A2 contained in the clear ink is 80% by mass or more relative to a total amount of the polymerizable compound. ### Claim 2 (depends on 1) The ink set according to claim 1, wherein a content of the Polymerizable oligomer A2 is 10% by mass or less relative to a total amount of the polymerizable compound contained in the clear ink. ### Claim 3 (depends on 1) The ink set according to claim 1, wherein a content of the Polymerizable monomer A1 is 70% by mass or more relative to a total amount of the polymerizable compound contained in the clear ink. ### Claim 4 (depends on 1) The ink set according to claim 1, wherein the polymerizable compound contained in the color ink contains a monofunctional monomer, and a total content of the monofunctional monomer contained in the color ink is 85% by mass or more relative to a total amount of the polymerizable compound contained in the color ink. ### Claim 5 (depends on 1) The ink set according to claim 1, wherein the Polymerizable oligomer A2 contains a urethane acrylate oligomer. ### Claim 6 (depends on 1) An ink jet method by using the ink set according to claim 1, the method comprising: a first ejecting step of ejecting the color ink from a liquid ejecting head so as to attach the color ink to a recording medium; a first curing step of applying radiation to the color ink attached to the recording medium, a second ejecting step of ejecting the clear ink from a liquid ejecting head so as to attach the clear ink to at least part of a region, to which the color ink is attached, of the recording medium; and a second curing step of applying radiation to the clear ink attached to the recording medium. ### Claim 7 (depends on 6) The ink jet method according to claim 6 comprising a leveling step of leaving the recording medium, to which the clear ink is attached, to stand between the second ejecting step and the second curing step.