# US 8,998,397 B2 · Ink, ink cartridge and ink jet recording method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,998,397 B2 - Document ID: US8998397B2 - Status: Granted - Kind: B2 - Application number: 13/530,504 - Filed: 2012-06-22 - Published: 2013-01-31 - Granted: 2015-04-07 - Earliest claimed: 2011-07-27 - Assignees: Canon Kabushiki Kaisha - Applicants: Yasuhito Mori; Tomohiro Yamashita - Inventors: Yasuhito Mori; Tomohiro Yamashita - Web page: https://patentgrep.com/patent/US8998397B2 ## CPC - C09D 11/38: characterised by non-macromolecular additives other than solvents, pigments or dyes - B41J 2/2107: {characterised by the ink properties (supplying ink in a solid state B41J2/17593)} - C09D 11/322: Pigment inks - 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 ## Abstract The invention provides an ink that inhibits lowering of ejection stability caused by a precipitate derived from a self-dispersible type monoazo pigment and also inhibits deterioration of a liquid contact surface of a heater portion of a recording head. The ink is an ink for ink jet recording system employing an thermal energy, containing a monoazo pigment, a resin and a surfactant represented by the following formula (1). A proportion of a molecular weight of an ethylene oxide group moiety occupying the surfactant is 10% or more and 85% or less, the monoazo pigment is a self-dispersible pigment to the particle surface of which at least one hydrophilic group selected from the group consisting of —COOM, —SO3M, —PO3HM and —PO3M2 is bonded directly or through another atomic group, and the acid value of the resin is 240 mg KOH/g or less. ## Claims ### Claim 1 An ink for use in an ink jet recording system in which ink is ejected from a recording head by an action of thermal energy, the ink comprising a monoazo pigment, a resin, and a surfactant represented by the following formula (1): wherein n is 1.0 or more, and m is 1.0 or more, a proportion of a molecular weight of an ethylene oxide group moiety occupying the surfactant is 10% or more and 85% or less, the monoazo pigment is a self-dispersible pigment to a particle surface of which at least one hydrophilic group selected from the group consisting of —COOM, —SO3M, —PO3HM, and —PO 3M2 (M in the formula is a hydrogen atom, alkali metal, ammonium or organic ammonium) is bonded directly or through another atomic group, and a kind of the monoazo pigment is C.I. Pigment Yellow 74, and an acid value of the resin is 240 mg KOH/g or less. ### Claim 2 (depends on 1) The ink according to claim 1, wherein the monoazo pigment is a self-dispersible pigment to the particle surface of which at least one hydrophilic group selected from the group consisting of —COOM, —SO3M, —PO3HM, and —PO3M2 (M in the formula is a hydrogen atom, alkali metal, ammonium or organic ammonium) is bonded through at least one other atomic group selected from the group consisting of an alkylene group, an arylene group, an amide group, a sulfonyl group, an amino group, a carbonyl group, an ester group, and an ether group. ### Claim 3 (depends on 1) The ink according to claim 1, wherein a content (% by mass) of the resin in the ink is 0.25 times or more and 1.0 times or less in terms of mass ratio as much as the content (% by mass) of the monoazo pigment. ### Claim 4 (depends on 1) The ink according to claim 1, wherein the acid value of the resin is 170 mg KOH/g or less. ### Claim 5 (depends on 1) The ink according to claim 1, wherein m in the formula (1) is 10.0 or more and 60.0 or less. ### Claim 6 (depends on 1) The ink according to claim 1, wherein a content (% by mass) of the surfactant in the ink is 0.05 times or more and 0.5 times or less in terms of mass ratio as much as the content (% by mass) of the monoazo pigment. ### Claim 7 (depends on 1) The ink according to claim 1, wherein the proportion of the molecular weight of the ethylene oxide group moiety occupying the surfactant is 41% or more and 85% or less. ### Claim 8 (depends on 1) The ink according to claim 1, wherein the proportion of a molecular weight of an ethylene oxide group moiety occupying the surfactant is 57% or more and 85% or less. ### Claim 9 (depends on 1) An ink cartridge comprising an ink and an ink storage portion storing the ink, wherein the ink is the ink according to claim 1. ### Claim 10 (depends on 1) An ink jet recording method comprising ejecting an ink from a recording head of an ink jet system by an action of thermal energy to record an image on a recording medium, wherein the ink is the ink according to claim 1. ### Claim 11 (depends on 1) The ink according to claim 1, wherein the acid value of the resin is 100 mg KOH/g or more. ### Claim 12 (depends on 1) The ink according to claim 1, wherein the content (% by mass) of the resin in the ink is 1.0% by mass or more and 5.0% by mass or less. ### Claim 13 (depends on 1) The ink according to claim 1, wherein the content (% by mass) of the monoazo pigment in the ink is 2.5% by mass or more and 10.0% by mass or less. ### Claim 14 (depends on 1) The ink according to claim 1, wherein the content (% by mass) of the surfactant represented by the formula (1) is 0.05% by mass or more and 5.0% by mass or less. ### Claim 15 (depends on 1) The ink according to claim 1, wherein the surfactant represented by the formula (1) has a block of the ethylene oxide group moiety bonded to both ends of the propylene oxide group. ### Claim 16 (depends on 1) The ink according to claim 1, wherein the n in the surfactant represented by the formula (1) is 7.9 or more and 450.0 or less. ### Claim 17 (depends on 1) The ink according to claim 1, wherein the m in the surfactant represented by the formula (1) is 10.0 or more and 60.0 or less.