# US 12,110,405 B2 · Aqueous dispersion, method of manufacturing aqueous dispersion, and ink > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,110,405 B2 - Document ID: US12110405B2 - Status: Granted - Kind: B2 - Application number: 17/476,724 - Filed: 2021-09-16 - Published: 2022-04-07 - Granted: 2024-10-08 - Earliest claimed: 2020-10-01 - Assignees: Ricoh Company, Ltd. - Applicants: Ryo Miyakoshi; Takuya Yamazaki; Chikako Hatta - Inventors: Ryo Miyakoshi; Takuya Yamazaki; Chikako Hatta - Web page: https://patentgrep.com/patent/US12110405B2 ## CPC - C09D 11/324: containing carbon black - C09D 11/326: characterised by the pigment dispersant - C08L 67/00: Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain (of polyester-amides C08L77/12; of polyester-imides C08L79/08); Compositions of derivatives of such polymers - C09D 11/104: Polyesters - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B82Y 40/00: Manufacture or treatment of nanostructures - 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) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES ## Abstract An aqueous dispersion contains emulsion resin particles that contains pigment enclosing emulsion resin particles enclosing an inorganic pigment, wherein the pigment enclosing emulsion resin particles have a 50 percent cumulative volume particle diameter (D50) of from 40 to 300 nm as measured by laser diffraction scattering method, wherein the pigment enclosing emulsion resin particles have an average aspect ratio of from 1.0 to 1.5. ## Claims ### Claim 1 An aqueous dispersion comprising: emulsion resin particles comprising: pigment enclosing emulsion resin particles each comprising: a resin; and an inorganic pigment enclosed in the resin, wherein the pigment enclosing emulsion resin particles have a 50 percent cumulative volume particle diameter (D50) of from 40 to 300 nm as measured by a laser diffraction scattering method, wherein the pigment enclosing emulsion resin particles have an average aspect ratio of from 1.0 to 1.5. ### Claim 2 (depends on 1) The aqueous dispersion according to claim 1, wherein the inorganic pigment comprises carbon black. ### Claim 3 (depends on 1) The aqueous dispersion according to claim 1, wherein a mass ratio of the inorganic pigment to the resin in the aqueous dispersion is from 0.20 to 0.75, wherein a pigment exposure ratio is 8 percent or less by the following calculation: the aqueous dispersion containing pigment enclosing emulsion resin particles is adjusted to have a solid content concentration of 10.75 percent by mass; the aqueous dispersion is applied to coated paper followed by drying at 25 degrees C. to obtain a coated film; without electroconductivity treatment, the coated film is observed by a scanning electron microscope equipped with back-scattered electron detector at an acceleration voltage of 0.75 kV and 20,000×magnification; an image of the coated film observed is digitized to calculate a pigment area thereof; and a ratio of the inorganic pigment at a surface of the coated film is determined as the pigment exposure ratio. ### Claim 4 (depends on 1) The aqueous dispersion according to claim 1, wherein the pigment enclosing emulsion resin particles account for 30 percent by number or greater of the emulsion resin particles having a particle diameter of 50 nm or greater. ### Claim 5 (depends on 1) The aqueous dispersion according to claim 1, wherein the emulsion resin particles comprise polyester. ### Claim 6 (depends on 5) The aqueous dispersion according to claim 5, wherein the polyester has a carboxyl group and is a self-emulsifying resin. ### Claim 7 (depends on 1) A method of manufacturing the aqueous dispersion of claim 1, comprising: mixing a pigment, a pigment dispersant, and an organic solvent to obtain a pigment pre-dispersion having a 50 percent cumulative volume particle diameter (D50) of from 10 to 150 nm; mixing the pigment pre-dispersion and a resin to obtain a pigment-dispersed resin solution; mixing the pigment-dispersed resin solution with water to obtain a liquid dispersion containing pigment enclosing emulsion resin particles in which the pigment is enclosed in the resin; and purging the liquid dispersion of the organic solvent to obtain the aqueous dispersion. ### Claim 8 (depends on 1) An ink comprising: the aqueous dispersion of claim 1. ### Claim 9 (depends on 1) The aqueous dispersion according to claim 1, wherein the inorganic pigment is not dispersed in the resin.