# US 8,569,394 B2 · Active light-curable ink composition, and ink jet, ink jet printing apparatus and ink jet recording method using the light-curable ink composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,394 B2 - Document ID: US8569394B2 - Status: Granted - Kind: B2 - Application number: 12/396,553 - Filed: 2009-03-03 - Published: 2009-09-10 - Granted: 2013-10-29 - Earliest claimed: 2008-03-04 - Assignees: Seiko Epson Corporation - Applicants: Satoru Miura - Inventors: Satoru Miura - Web page: https://patentgrep.com/patent/US8569394B2 ## CPC - 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 11/40: Ink-sets specially adapted for multi-colour inkjet printing - 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 An active light-curable ink composition contains a polymerizable compound, a color material having an absorption peak in a wavelength region, and a polymerization initiator having an absorption peak in a different wavelength region from the color material. ## Claims ### Claim 1 An ink set comprising a plurality of active light-curable ink compositions, including: a yellow ink composition comprising a yellow color material having an absorption peak in a wavelength region of 370 to 390 nm, a polymerizable compound and a polymerization initiator having an absorption peak in a different wavelength region from the yellow color material, the polymerization initiator for the yellow ink composition comprising isoamino-P-dimethylaminobenzoate ester, α-aminoalkylphenone, oxime ester, or aminobenzoate, wherein when the absorbance of the absorption peak of the yellow color material is defined to be 1, the absorption peak of the polymerization initiator of the yellow ink composition lies in a wavelength region where the yellow color material exhibits an absorbance of 0.6 or less; a magenta ink composition comprising a magenta color material having an absorption peak in a wavelength region of 550 to 570 nm, a polymerizable compound and a polymerization initiator having an absorption peak in a different wavelength region from the magenta color material, the polymerization initiator for the magenta ink composition comprising thioxanthone, wherein when the absorbance of the absorption peak of the magenta color material is defined to be 1, the absorption peak of the polymerization initiator of the magenta ink composition lies in a wavelength region where the magenta color material exhibits an absorbance of 0.5 or less; and a cyan ink composition comprising a cyan color material having an absorption peak in a wavelength region of 330 to 350 nm, a polymerizable compound and a polymerization initiator having an absorption peak in a different wavelength region from the cyan color material, the polymerization initiator for the cyan ink composition comprising α-hydroxyalkylphenone or anthraquinone, wherein when the absorbance of the absorption peak of the cyan color material is defined to be 1, the absorption peak of the polymerization initiator of the cyan ink composition lies in a wavelength region where the cyan color material exhibits an absorbance of 0.6 or less. ### Claim 2 (depends on 1) The ink set according to claim 1, further comprising (d) an active light-curable white ink composition containing a polymerizable compound, a white material having an absorption peak in a wavelength region, and a polymerization initiator having an absorption peak in the wavelength region where the white color material has the absorption peak. ### Claim 3 (depends on 2) The ink set according to claim 2, wherein the polymerization initiator of the white ink composition has an absorption peak in the wavelength region where the white material exhibits an absorbance higher than the absorbance in the UV-visible region of 300 to 350 nm. ### Claim 4 (depends on 2) The ink set according to claim 2, wherein the polymerization initiator in the active light-curable white ink composition has an absorption peak in the wavelength region of 350 to 450 nm. ### Claim 5 (depends on 1) The ink set according to claim 1, further comprising: (e) an active light-curable clear ink composition containing at least one polymerizable compound and a polymerization initiator, but not containing a color material, wherein the polymerization initiator of the active light-curable clear ink composition has an absorption peak in a wavelength region different from the wavelength region where the highest absorption peak of the at least one polymerizable compound of the active light-curable clear ink composition lies. ### Claim 6 (depends on 1) An ink jet printing apparatus comprising the ink set of claim 1. ### Claim 7 (depends on 1) An ink jet recording method comprising providing the ink set as set forth in claim 1, ejecting droplets of each of the plurality of active light-curable ink compositions onto a recording medium and irradiating the ejected ink compositions with active light. ### Claim 8 An ink set comprising a plurality of active light-curable ink compositions, including: a yellow ink composition comprising a yellow color material having an absorption peak in a wavelength region of 370 to 390 nm, a polymerizable compound and a polymerization initiator having an absorption peak in a different wavelength region from the yellow color material, the polymerization initiator for the yellow ink composition comprising isoamino-P-dimethylaminobenzoate ester, α-aminoalkylphenone, oxime ester, or aminobenzoate wherein the polymerization initiator of the yellow ink composition has an absorption peak in a wavelength region of 300 to 350 nm; a magenta ink composition comprising a magenta color material having an absorption peak in a wavelength region of 550 to 570 nm, a polymerizable compound and a polymerization initiator having an absorption peak in a different wavelength region from the magenta color material, the polymerization initiator for the magenta ink composition comprising thioxanthone, wherein the polymerization initiator of the magenta ink composition has an absorption peak in a wavelength region of 350 to 450 nm; and a cyan ink composition comprising a cyan color material having an absorption peak in a wavelength region of 330 to 350 nm, a polymerizable compound and a polymerization initiator having an absorption peak in a different wavelength region from the cyan color material, the polymerization initiator for the cyan ink composition comprising α-hydroxyalkylphenone or anthraquinone, wherein the polymerization initiator of the cyan ink composition has an absorption peak in a wavelength region of 275 to 300 nm. ### Claim 9 (depends on 8) The ink set according to claim 8, further comprising (f) an active light-curable white ink composition containing a polymerizable compound, a white material having an absorption peak in a wavelength region, and a polymerization initiator having an absorption peak in the wavelength region where the white color material has the absorption peak. ### Claim 10 (depends on 9) The ink set according to claim 9, wherein the polymerization initiator of the white ink composition has an absorption peak in the wavelength region where the white material exhibits an absorbance higher than the absorbance in the UV-visible region of 300 to 350 nm. ### Claim 11 (depends on 9) The ink set according to claim 9, wherein the polymerization initiator in the active light-curable white ink composition has an absorption peak in the wavelength region of 350 to 450 nm. ### Claim 12 (depends on 8) The ink set according to claim 8, further comprising: (g) an active light-curable clear ink composition containing at least one polymerizable compound and a polymerization initiator, but not containing a color material, wherein the polymerization initiator of the active light-curable clear ink composition has an absorption peak in a wavelength region different from the wavelength region where the highest absorption peak of the at least one polymerizable compound of the active light-curable clear ink composition lies. ### Claim 13 (depends on 8) An ink jet printing apparatus comprising the ink set of claim 8. ### Claim 14 (depends on 8) An ink jet recording method comprising providing the ink set as set forth in claim 8, ejecting droplets of each of the plurality of active light-curable ink compositions onto a recording medium and irradiating the ejected ink compositions with active light. ### Claim 15 (depends on 1) The ink set according to claim 1, wherein the polymerization initiator for the yellow ink composition consists of isoamino-P-dimethylaminobenzoate ester, α-aminoalkylphenone, oxime ester, or aminobenzoate, the polymerization initiator for the magenta ink composition consists of thioxanthone and the polymerization initiator for the cyan ink composition consists of α-hydroxyalkylphenone or anthraquinone.