# US 9,434,851 B2 · Ink set for inkjet recording and inkjet recording method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,434,851 B2 - Document ID: US9434851B2 - Status: Granted - Kind: B2 - Application number: 14/622,052 - Filed: 2015-02-13 - Published: 2015-08-20 - Granted: 2016-09-06 - Earliest claimed: 2014-02-20 - Assignees: KYOCERA Document Solutions Inc. - Applicants: KYOCERA Document Solutions Inc. - Inventors: Noriaki Ozawa - Web page: https://patentgrep.com/patent/US9434851B2 ## CPC - C09D 11/328: characterised by dyes - C08K 3/04: Carbon - C08K 5/42: Sulfonic acids; Derivatives thereof - C09D 11/10: based on artificial resins - C09D 11/324: containing carbon black - C09D 11/326: characterised by the pigment dispersant - C09D 11/40: Ink-sets specially adapted for multi-colour inkjet printing - C09D 179/02: Polyamines - C08K 9/04: Ingredients treated with organic substances {(treated with macromolecular compounds C08K9/08)} - 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) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) ## Abstract An ink set for inkjet recording includes: a first ink containing a black dye and a polyamine; and a second ink containing a black pigment having a coat of an anionic resin. An inkjet recording method includes: ejecting a first ink containing a black dye and a polyamine onto a recording medium through an inkjet recording head; and ejecting a second ink containing a black pigment having a coat of an anionic resin onto the first ink ejected on the recording medium through an inkjet recording head. ## Claims ### Claim 1 An ink set for inkjet recording, comprising: a first ink containing a black dye and a polyamine having a mass average molecular weight of no less than 5000 and no greater than 15000; and a second ink containing a black pigment having a coat of an anionic resin, wherein the first ink is an ink that is ejected onto a recording medium, the second ink is an ink that is ejected onto the first ink ejected on the recording medium, the first ink and the second ink are not mixed together before the second ink is ejected onto the first ink ejected on the recording medium, and the first ink and the second ink are mixed together on the recording medium after the second ink is ejected onto the first ink ejected on the recording medium. ### Claim 2 (depends on 1) An ink set according to claim 1, wherein the black dye is a direct dye, and the black pigment is carbon black. ### Claim 3 (depends on 1) An ink set according to claim 1, wherein no less than 93% by mass of the anionic resin is adsorbed to the black pigment, and the anionic resin has a mass average molecular weight of no less than 20000. ### Claim 4 (depends on 1) An ink set according to claim 1, wherein an amount of the polyamine contained in the first ink is no less than 0.05% by mass and no greater than 0.5% by mass relative to the total mass of the first ink. ### Claim 5 An inkjet recording method, comprising: ejecting a first ink containing a black dye and a polyamine having a mass average molecular weight of no less than 5000 and no greater than 15000 onto a recording medium through an inkjet recording head; and ejecting a second ink containing a black pigment having a coat of an anionic resin onto the first ink ejected on the recording medium through an inkjet recording head. ### Claim 6 (depends on 5) An inkjet recording method according to claim 5, wherein the black dye is a direct dye, and the black pigment is carbon black. ### Claim 7 (depends on 5) An inkjet recording method according to claim 5, wherein no less than 93% by mass of the anionic resin is adsorbed to the black pigment, and the anionic resin has a mass average molecular weight of no less than 20000. ### Claim 8 (depends on 5) An inkjet recording method according to claim 5, wherein an amount of the polyamine contained in the first ink is no less than 0.05% by mass and no greater than 0.5% by mass relative to the total mass of the first ink. ### Claim 9 (depends on 1) An ink set according to claim 1, wherein the anionic resin is located on surfaces of particles of the black pigment. ### Claim 10 (depends on 1) An ink set according to claim 1, wherein the anionic resin is located on surfaces of particles of the black pigment, and the anionic resin is a styrene-acrylic resin. ### Claim 11 (depends on 5) An inkjet recording method according to claim 5, wherein the anionic resin is located on surfaces of particles of the black pigment. ### Claim 12 (depends on 5) An inkjet recording method according to claim 5, wherein the anionic resin is located on surfaces of particles of the black pigment, and the anionic resin is a styrene-acrylic resin. ### Claim 13 (depends on 1) An ink set according to claim 1, wherein the first ink further contains triethylene glycol monobutyl ether and 2-pyrrolidone, and the second ink further contains triethylene glycol monobutyl ether and 2-pyrrolidone. ### Claim 14 (depends on 5) An inkjet recording method according to claim 5, wherein the first ink further contains triethylene glycol monobutyl ether and 2-pyrrolidone, and the second ink further contains triethylene glycol monobutyl ether and 2-pyrrolidone. ### Claim 15 (depends on 1) An ink set according to claim 1, wherein the second ink is an ink that is ejected onto the first ink that has been ejected and landed on the recording medium, the first ink and the second ink are not mixed together before the second ink is ejected onto the first ink that has been ejected and landed on the recording medium, and the first ink and the second ink are mixed together on the recording medium after the second ink is ejected onto the first ink that has been ejected and landed on the recording medium.