# US 8,465,578 B2 · Inkjet printing ink set > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,578 B2 - Document ID: US8465578B2 - Status: Granted - Kind: B2 - Application number: 13/076,940 - Filed: 2011-03-31 - Published: 2012-10-04 - Granted: 2013-06-18 - Earliest claimed: 2011-03-31 - Assignees: Eastman Kodak Company - Applicants: Barbara Boland Lussier - Inventors: Barbara Boland Lussier - Web page: https://patentgrep.com/patent/US8465578B2 ## CPC - C09D 11/40: Ink-sets specially adapted for multi-colour inkjet printing - C09D 11/322: Pigment inks - C09D 11/38: characterised by non-macromolecular additives other than solvents, pigments or dyes - 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 process for printing an image includes printing a substrate with an aqueous inkjet ink and drying the printed image with a near-infrared drying system, wherein the inkjet ink is a yellow or magenta inkjet ink and comprises a yellow or magenta colorant and a distinct near-infrared absorbing compound. Inkjet ink sets for use with an inkjet printing system employing a near-infrared drying system in the process include at least a black ink and a yellow ink, wherein the yellow ink comprises a yellow colorant and dispersed nanoparticulate colloidal silica at a concentration of from 0.1 to about 10 wt %, and the black ink comprises a black colorant and dispersed nanoparticulate colloidal silica at a concentration of from 0 wt. % to at most ½ of the wt. % of the dispersed nanoparticulate colloidal silica in the yellow ink. Various embodiments provide a process for inkjet printing and drying inks with improved absorption in the near-IR region of the spectrum for improved drying performance of aqueous, hypsochromic inks, and an inkjet ink set with improved balanced near-IR drying of black and yellow inkjet inks. ## Claims ### Claim 1 An inkjet ink set for use with an inkjet printing system employing a near-infrared drying system, comprising at least a black ink and a yellow ink, wherein the yellow ink comprises a yellow colorant and dispersed nanoparticulate colloidal silica at a concentration of from 0.1 to about 10 wt %, and the black ink comprises a black colorant and dispersed nanoparticulate colloidal silica at a concentration of from 0 wt. % to at most ½ of the wt. % of the dispersed nanoparticulate colloidal silica in the yellow ink, wherein the dispersed nanoparticulate colloidal silica comprises hydrated silica particles which are absorbing in the near-IR spectrum from 750 nm to 900 nm, and wherein the pH of the inks is greater than 7.5 and less than 9.0 so as to obtain improved drying with the near-infrared drying system. ### Claim 2 (depends on 1) The inkjet ink set of claim 1, wherein the yellow ink comprises dispersed nanoparticulate colloidal silica at a concentration of from about 1 to 5 wt %. ### Claim 3 (depends on 1) The inkjet ink set of claim 1, wherein the yellow ink comprises dispersed nanoparticulate colloidal silica at a concentration of from about 1 to 4 wt %. ### Claim 4 (depends on 1) The inkjet ink set of claim 1, wherein the nanoparticulate colloidal silica comprises non porous particles having an average particle size of less than 100 nm. ### Claim 5 (depends on 1) The inkjet ink set of claim 1, wherein the nanoparticulate colloidal silica comprises non porous particles having an average particle size of less than 50 nm. ### Claim 6 (depends on 1) The inkjet ink set of claim 1, wherein the yellow ink comprises dispersed yellow pigment particles. ### Claim 7 (depends on 6) The inkjet ink set of claim 6, wherein the black colorant of the black ink comprises carbon black. ### Claim 8 (depends on 7) The inkjet ink set of claim 7, wherein the black ink comprises 0 wt % dispersed nanoparticulate colloidal silica. ### Claim 9 (depends on 6) The inkjet ink set of claim 6, wherein the yellow pigment particles are dispersed with a polymeric dispersant, are dispersed with a surfactant, or are self dispersed without the need for a separate dispersant. ### Claim 10 (depends on 1) The inkjet ink set of claim 1, wherein the black colorant of the black ink comprises carbon black. ### Claim 11 (depends on 1) The inkjet ink set of claim 1, further comprising a magenta ink and a cyan ink. ### Claim 12 (depends on 11) The inkjet ink set of claim 11, wherein the magenta ink comprises dispersed nanoparticulate colloidal silica at a concentration of from 0.1 to about 10 wt %, and the black ink comprises dispersed nanoparticulate colloidal silica at a concentration of from 0 wt. % to at most ½ of the wt. % of the dispersed nanoparticulate colloidal silica in the magenta ink. ### Claim 13 (depends on 12) The inkjet ink set of claim 12, wherein the cyan ink comprises dispersed nanoparticulate colloidal silica at a concentration of from 0 wt. % to at most ½ of the wt. % of the dispersed nanoparticulate colloidal silica in the yellow ink. ### Claim 14 (depends on 13) The inkjet ink set of claim 13, wherein the cyan ink comprises 0 wt % dispersed nanoparticulate colloidal silica. ### Claim 15 (depends on 11) The inkjet ink set of claim 11, wherein the cyan ink comprises dispersed nanoparticulate colloidal silica at a concentration of from 0 wt. % to at most ½ of the wt. % of the dispersed nanoparticulate colloidal silica in the yellow ink. ### Claim 16 (depends on 15) The inkjet ink set of claim 15, wherein the cyan ink comprises 0 wt % dispersed nanoparticulate colloidal silica.