# US 10,245,852 B2 · Photo-curable ink jet ink set and ink jet recording method using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,245,852 B2 - Document ID: US10245852B2 - Status: Granted - Kind: B2 - Application number: 15/629,028 - Filed: 2017-06-21 - Published: 2017-10-12 - Granted: 2019-04-02 - Earliest claimed: 2012-02-29 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Keitaro Nakano; Jun Ito - Web page: https://patentgrep.com/patent/US10245852B2 ## CPC - C09D 11/30: Inkjet printing inks - B41J 2/17: characterised by ink handling {(cleaning by driving a fluid through the nozzles to the outside thereof B41J2/1652; for treating before, during or after printing or for uniform coating or laminating the copy material before or after printing B41J11/0015)} - B41J 2/21: for multi-colour printing - B41J 2/2107: {characterised by the ink properties (supplying ink in a solid state B41J2/17593)} - B41J 2/2117: {Ejecting white liquids} - B41J 2/515: line printer type - 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 11/322: Pigment inks - C09D 11/38: characterised by non-macromolecular additives other than solvents, pigments or dyes - C09D 11/40: Ink-sets specially adapted for multi-colour inkjet printing - C09D 133/08: Homopolymers or copolymers of acrylic acid esters - B41J 2/2114: {Ejecting specialized liquids, e.g. transparent or processing liquids (B41J2/211 takes precedence)} - B41J 11/00214: {using UV radiation} - B41J 2025/008: {comprising a plurality of print heads placed around a drum} - 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 ## Abstract A photo-curable ink jet ink set includes an undercoating photo-curable ink jet ink containing a (meth)acrylic acid ester having a vinyl ether group expressed by general formula (I), and an overcoating photo-curable ink jet ink. The undercoating photo-curable ink jet ink has a higher surface tension than the overcoating photo-curable ink jet ink. ## Claims ### Claim 1 An ink jet recording method using a photo-curable ink jet ink set comprising a first photo-curable ink jet ink and a second photo-curable ink jet ink, the method comprising: ejecting the first photo-curable ink jet ink onto a recording medium, the first photo-curable ink jet ink comprising a white ink; ejecting the second photo-curable ink jet ink onto the first photo-curable ink jet ink ejected onto the recording medium, wherein the second photo-curable ink jet ink comprises a non-white, color ink; and curing the first photo-curable ink jet ink and the second photo-curable ink jet ink; the curing being conducted using a UV-LED having an emission peak at a wavelength in the range of 350 to 420 nm; wherein the first photo-curable ink jet ink has a surface tension and contains a (meth) acrylic acid ester having a vinyl ether group expressed by general formula (I): CH2═CR1—COOR2—O—CH═CH—R3, wherein R1 represents a hydrogen atom or a methyl group, R2 represents a divalent organic residue having a carbon number of 2 to 20, and R3 represents a hydrogen atom or a monovalent organic residue having a carbon number of 1 to 11; and the second photo-curable ink jet ink has a surface tension, wherein the surface tension of the first photo-curable ink jet ink is higher than the surface tension of the second photo-curable ink jet ink. ### Claim 2 (depends on 1) The ink jet recording method of claim 1, wherein the first photo-curable ink jet ink and the second photo-curable ink jet ink contain a photopolymerization initiator comprising acylphosphine oxide compound. ### Claim 3 (depends on 1) The ink jet recording method of claim 1, wherein a total content of a photopolymerization initiator in the first photo-curable ink jet ink and a photopolymerization initiator in the second photo-curable ink jet ink is 3% to 20% by mass relative to the total mass of the ink jet ink. ### Claim 4 (depends on 1) The ink jet recording method of claim 1, wherein the first photo-curable ink jet ink and the second photo-curable ink jet ink contain a photopolymerization initiator comprising bis (2,4,6-trimethylbenzoyl)phenylphosphine oxide. ### Claim 5 (depends on 1) The ink jet recording method of claim 1, wherein the surface tension of the first photo-curable ink jet ink is in the range of 20 to 40 mN/m and the surface tension of the second photo-curable ink jet ink in the range of 20 to 40 mN/m. ### Claim 6 (depends on 1) The ink jet recording method of claim 1, wherein the first photo-curable ink jet ink further comprises a monofunctional (meth) acrylate other than the (meth) acrylic acid ester having a vinyl ether group as a polymerizable compound. ### Claim 7 (depends on 6) The ink jet recording method of claim 6, wherein a content of the monofunctional (meth) acrylate is from 10% to 90% by mass relative to the total mass of the ink. ### Claim 8 (depends on 1) The ink jet recording method of claim 1, wherein the first photo-curable ink jet ink further comprises a bifunctional or trifunctional or more (meth) acrylate. ### Claim 9 (depends on 1) The ink jet recording method of claim 1, wherein a viscosity of the first photo-curable ink jet ink and a viscosity of the second photo-curable ink jet ink are 15 mPa·s or less at the ejecting. ### Claim 10 (depends on 1) The ink jet recording method of claim 1, wherein the recording medium is transported to a position opposing a first head unit, the first head unit ejects the first photo-curable ink to the recording medium, the recording medium is transported to a portion opposing a second head unit, and the second head unit ejects the second photo-curable ink to the recording medium. ### Claim 11 (depends on 1) The ink jet recording method of claim 1, wherein a difference in surface tension between the first photo-curable ink jet ink and the second photo-curable ink jet ink is 5 mN/m or more. ### Claim 12 (depends on 1) The ink jet recording method of claim 1, wherein a content of the (meth) acrylic acid ester expressed by general formula (I) in the first photo-curable ink jet ink is 20% to 80% by mass relative to the total mass of the first photo-curable ink jet ink. ### Claim 13 (depends on 1) The ink jet recording method of claim 1, wherein the second photo-curable ink jet ink contains a (meth) acrylic acid ester having a vinyl ether group expressed by general formula (I) in a lower content than the content of the (meth) acrylic acid ester in the first photo-curable ink jet ink. ### Claim 14 (depends on 1) The ink jet recording method of claim 1, wherein the first photo-curable ink jet ink contains an acrylic surfactant. ### Claim 15 (depends on 1) The ink jet recording method of claim 1, wherein the second photo-curable ink jet ink contains a silicone surfactant. ### Claim 16 (depends on 1) The ink jet recording method of claim 1, wherein the second photo-curable ink jet ink is a nonwhite ink containing a nonwhite coloring material. ### Claim 17 (depends on 1) The ink jet recording method of claim 1, wherein the second photo-curable ink jet ink contains a coloring material in a range from 0.5 to 20% by mass relative to the total mass of second ink jet ink. ### Claim 18 (depends on 5) The ink jet recording method of claim 5, wherein the second photo-curable ink jet ink contains at least one of an organic pigment or an inorganic pigment as the coloring material.