# US 12,600,876 B2 · White ink for inkjet printing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,600,876 B2 - Document ID: US12600876B2 - Status: Granted - Kind: B2 - Application number: 18/416,184 - Filed: 2024-01-18 - Published: 2024-07-25 - Granted: 2026-04-14 - Earliest claimed: 2023-01-19 - Assignees: KYOCERA Document Solutions Inc. - Applicants: KYOCERA Document Solutions Inc. - Inventors: Yukari Kida - Web page: https://patentgrep.com/patent/US12600876B2 ## CPC - C09D 11/322: Pigment inks - B41J 2/01: Ink jet - B41M 5/0023: {Digital printing methods characterised by the inks used (inks per se C09D11/00)} - B41M 5/0047: {by ink-jet printing} - C09D 11/102: containing macromolecular compounds obtained by reactions other than those only involving unsaturated carbon-to-carbon bonds - C09D 11/107: from unsaturated acids or derivatives thereof - 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 A white ink for inkjet printing contains titanium oxide particles and an aqueous medium. The titanium oxide particles include anatase-type titanium oxide particles and rutile-type titanium oxide particles. The anatase-type titanium oxide particles have a percentage content of at least 17.50% by mass and no greater than 37.50% by mass in the titanium oxide particles. The rutile-type titanium oxide particles have a percentage content of at least 72.50% by mass and no greater than 82.50% by mass in the titanium oxide particles. Both the anatase-type titanium oxide particles and the rutile-type titanium oxide particles have a number average primary particle diameter of at least 140 nm and no greater than 340 nm. ## Claims ### Claim 1 A white ink for inkjet printing, comprising: titanium oxide particles; and an aqueous medium, wherein the titanium oxide particles are dispersed into the aqueous medium, the titanium oxide particles include anatase-type titanium oxide particles and rutile-type titanium oxide particles, the anatase-type titanium oxide particles have a percentage content of at least 17.50% by mass and no greater than 37.50% by mass in the titanium oxide particles, the rutile-type titanium oxide particles have a percentage content of at least 72.50% by mass and no greater than 82.50% by mass in the titanium oxide particles, both the anatase-type titanium oxide particles and the rutile-type titanium oxide particles have a number average primary particle diameter of at least 140 nm and no greater than 340 nm, and a ratio of major axis length to minor axis length of the anatase-type titanium oxide particles and a ratio of major axis length to minor axis length of the rutile-type titanium oxide particles each are at least 2 and no greater than 17. ### Claim 2 (depends on 1) The white ink for inkjet printing according to claim 1, wherein the number average primary particle diameter of the rutile-type titanium oxide particles is greater than the number average primary particle diameter of the anatase-type titanium oxide particles. ### Claim 3 (depends on 1) The white ink for inkjet printing according to claim 1, wherein the ratio of the major axis length to the minor axis length of the rutile-type titanium oxide particles is at least 3 and no greater than 17. ### Claim 4 (depends on 1) The white ink for inkjet printing according to claim 1, wherein the ratio of the major axis length to the minor axis length of the anatase-type titanium oxide particles is at least 3 and no greater than 17. ### Claim 5 (depends on 1) The white ink for inkjet printing according to claim 1, further comprising a pigment dispersion resin. ### Claim 6 (depends on 1) The white ink for inkjet printing according to claim 1, further comprising binder resin particles. ### Claim 7 (depends on 1) The white ink for inkjet printing according to claim 1, wherein the white ink for inkjet printing is used for front printing. ### Claim 8 (depends on 1) The white ink for inkjet printing according to claim 1, wherein the anatase-type titanium oxide particles have a percentage content of at least 22.00% by mass and no greater than 32.00% by mass in the titanium oxide particles, the rutile-type titanium oxide particles have a percentage content of at least 68.00% by mass and no greater than 78.00% by mass in the titanium oxide particles, the anatase-type titanium oxide particles have a number average primary particle diameter of at least 165 nm and no greater than 300 nm, the rutile-type titanium oxide particles have a number average primary particle diameter of at least 140 nm and no greater than 340 nm, and the number average primary particle diameter of the rutile-type titanium oxide particles is greater than the number average primary particle diameter of the anatase-type titanium oxide particles.