# US 2010/0165019 A1 · Ink jet recording ink, ink jet image-forming method and ink jet recording apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0165019 A1 - Document ID: US20100165019A1 - Status: Published application - Kind: A1 - Application number: 12/600,893 - Filed: 2008-07-22 - Published: 2010-07-01 - Earliest claimed: 2007-07-23 - Assignees: Canon Kabushiki Kaisha - Inventors: Shoji Koike; Ryota Kato; Hitoshi Yoshino - Web page: https://patentgrep.com/patent/US20100165019A1 ## CPC - B41M 5/0023: {Digital printing methods characterised by the inks used (inks per se C09D11/00)} - C09D 11/322: Pigment inks - 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) - 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 The invention provides an ink jet recording ink containing a self-dispersion pigment, to the surface of which an anionic functional group represented by the following general formula (I) has been bonded directly or through another atomic group, water, a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.37 or more as defined by the following equation (A) and a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.25 or less as defined by the equation (A), and having a surface tension of 34 mN/m or less. wherein M1 and M2 are, independently of each other, a hydrogen atom, alkali metal, ammonium or organic ammonium; Coefficient of hydrophilicity-hydrophobicity=[(Water activity value of a 20% aqueous solution)−(Molar fraction of water in the 20% aqueous solution)]/[1−(Molar fraction of water in the 20% aqueous solution)] ## Claims ### Claim 1 An ink jet recording ink comprising (a) a self-dispersion pigment, to the surface of which an anionic functional group represented by the following general formula (I) has been bonded directly or through another atomic group, (b) water, (c) a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.37 or more as defined by the following equation (A), (d) a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.25 or less as defined by the equation (A), and (e) an ethylene oxide adduct of acetylene glycol having a HLB value of 10 or more, the ink-jet recording ink having a surface tension of 34 mN/m or less, wherein the water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.37 or more is a water-soluble compound having a glycol structure of a hydrocarbon having 4 to 7 carbon atoms, the proportion (A)/(B) of the content of the water-soluble compound (A) to the content of the water-soluble compound (B) in the ink is 1/5 or more and 5/1 or less, and the ethylene oxide adduct of acetylene glycol is contained in the ink in an amount of 0.2% by mass or more and 5% by mass or less: wherein M1 and M2 are, independently of each other, a hydrogen atom, alkali metal, ammonium, or organic ammonium; Coefficient of hydrophilicity-hydrophobicity=[(Water activity value of a 20% aqueous solution)×(Molar fraction of water in the 20% aqueous solution)]/[1−(Molar fraction of water in the 20% aqueous solution)]. Equation (A) ### Claim 2 (depends on 1) The ink jet recording ink according to claim 1, which further comprises a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.26 or more, but less than 0.37 as defined by the equation (A). ### Claim 3 (depends on 1) The ink jet recording ink according to claim 1, wherein the particle size of the self-dispersion pigment is from 60 nm or more to 145 nm or less. ### Claim 4 (depends on 1) An ink jet image-forming method for forming an image by applying the ink jet recording ink according to claim 1 in a fixed amount of from 0.5 pl or more to 6.0 pl or less to plain paper, wherein the application of the ink is divided into plural times when an image having a portion where the ink is applied in a duty of 80% or more and in an amount of 5.0 μl/cm2 or less in total is formed in a basic matrix for forming the image, and the amount of the ink applied at each of the times divided is 0.7 μl/cm2 or less. ### Claim 5 An ink jet image-forming method for forming an image by applying each of at least 4 color inks of black, cyan, magenta, and yellow in a fixed amount of from 0.5 pl or more to 6.0 pl or less for each ink to plain paper, wherein: each of the 4 color inks (1) comprise (a) a self-dispersion pigment, to the surface of which an anionic functional group represented by the following general formula (I) has been bonded directly or through another atomic group, (b) water, (c) a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.37 or more as defined by the following equation (A), (d) a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.25 or less as defined by the equation (A), and (e) an ethylene oxide adduct of acetylene glycol having a HLB value of 10 or more, and (2) has a surface tension of 34 mN/m or less, wherein the water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.37 or more is a water-soluble compound having a glycol structure of a hydrocarbon having 4 to 7 carbon atoms, the proportion (A)/(B) of the content of the water-soluble compound (A) to the content of the water-soluble compound (B) in the ink is 1/5 or more and 5/1 or less, and the ethylene oxide adduct of acetylene glycol is contained in the ink in an amount of 0.2% by mass or more and 5% by mass or less, and the application of the inks is divided into plural times when an image having a portion where the inks are applied in a duty of 80% or more and in an amount of 5.0 μl/cm2 or less in total is formed in a basic matrix for forming the image, and the amount of the inks applied at each of the times divided is 0.7 μl/cm2 or less: wherein M1 and M2 are, independently of each other, a hydrogen atom, alkali metal, ammonium, or organic ammonium; Coefficient of hydrophilicity-hydrophobicity=[(Water activity value of a 20% aqueous solution)×(Molar fraction of water in the 20% aqueous solution)]/[1−(Molar fraction of water in the 20% aqueous solution)]. Equation (A) ### Claim 6 (depends on 4) The ink jet image-forming method according to claim 4, wherein the resolution of the basic matrix is from 600 dpi or more to 4,800 dpi or less. ### Claim 7 (depends on 4) The ink jet image-forming method according to claim 4, wherein the number of times of division is from 2 times or more to 8 times or less. ### Claim 8 (depends on 4) The ink jet image-forming method according to claim 4, wherein the application of the ink is conducted by the action of thermal energy. ### Claim 9 (depends on 1) An ink jet recording apparatus equipped with a recording head for forming an image by applying the ink jet recording ink according to claim 1 in a fixed amount of from 0.5 pl or more to 6.0 pl or less to plain paper, wherein the apparatus comprises a control mechanism, by which the application of the ink is divided into plural times when an image having a portion where the ink is applied in a duty of 80% or more and in an amount of 5.0 ml/cm2 or less in total is formed in a basic matrix for forming the image, and the amount of the ink applied at each of the times divided is controlled to 0.7 μl/cm2 or less. ### Claim 10 An ink jet recording apparatus equipped with a recording head for forming an image by applying each of at least 4 color inks of black, cyan, magenta, and yellow in a fixed amount of from 0.5 pl or more to 6.0 pl or less for each ink to plain paper, wherein: the apparatus comprises a control mechanism, by which the application of the inks is divided into plural times when an image having a portion where the inks are applied in a duty of 80% or more and in an amount of 5.0 pl/cm2 or less in total is formed in a basic matrix for forming the image, and the amount of the inks applied at each of the times divided is controlled to 0.7 μl/cm2 or less, and each of the inks (1) comprises (a) a self-dispersion pigment, to the surface of which an anionic functional group represented by the following general formula (I) has been bonded directly or through another atomic group, (b) water, (c) a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.37 or more as defined by the following equation (A), (d) a water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.25 or less as defined by the equation (A), and (e) an ethylene oxide adduct of acetylene glycol having a HLB value of 10 or more, and (2) has a surface tension of 34 mN/m or less, wherein the water-soluble substance having a coefficient of hydrophilicity-hydrophobicity of 0.37 or more is a water-soluble compound having a glycol structure of a hydrocarbon having 4 to 7 carbon atoms, the proportion (A)/(B) of the content of the water-soluble compound (A) to the content of the water-soluble compound (B) in the ink is 1/5 or more and 5/1 or less, and the ethylene oxide adduct of acetylene glycol is contained in the ink in an amount of 0.2% by mass or more and 5% by mass or less: wherein M1 and M2 are, independently of each other, a hydrogen atom, alkali metal, ammonium, or organic ammonium; Coefficient of hydrophilicity-hydrophobicity=[(Water activity value of a 20% aqueous solution)×(Molar fraction of water in the 20% aqueous solution)]/[1−(Molar fraction of water in the 20% aqueous solution)]. Equation (A) ### Claim 11 (depends on 9) The ink jet recording apparatus according to claim 9, wherein the recording head is a recording head that the application of the ink(s) is conducted by the action of thermal energy.