# US 5,702,510 A · Aqueous ink of pigment type > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,702,510 A - Document ID: US5702510A - Status: Granted - Kind: A - Application number: 08/704,609 - Filed: 1996-09-18 - Granted: 1997-12-30 - Earliest claimed: 1995-02-20 - Assignees: Kao Corporation - Inventors: Satoshi Yoshida; Hideki Yanagi; Kouichi Sakai; Masayoshi Nawa - Web page: https://patentgrep.com/patent/US5702510A ## CPC - C09D 11/326: characterised by the pigment dispersant - 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 aqueous ink of a pigment type comprises a pigment, water, a water-soluble solvent and a sulfite, and may further comprise a dispersant. An example of the dispersant comprises a copolymer of a monomer (a) represented by general formula (A), and one or more monomers (b) selected from the group consisting of compounds represented by general formulae (B) and (C): ##STR1## wherein AO represents an oxyalkylene group having 2 to 3 carbon atoms, and n represents an integer of 110 to 300. ## Claims ### Claim 1 An aqueous ink, comprising: a pigment, water, a water-soluble solvent, a sulfite and a dispersant which is member selected from the group consisting of an anionic surface-active agent, a cationic surface-active agent, an amphoteric surface-active agent, a nonionic surface-active agent, protein, a natural rubber, a glucoxide, a cellulose derivative, a lignin, sulfonate, a natural polymer, a nonioinic polymer and a copolymer of a monomer (a), represented by the formula (A), and one or more monomers (b) selected from the group consisting of compounds represented by formulae (B) and (C): ##STR4## wherein R.sub.1, and R.sub.2, which may be the same or different, each represent a hydrogen atom or a methyl group, m.sub.1 represents an integer of 0 to 2, AO represents an oxyalkylene group having 2 to 3 carbon atoms, n represents an integer of 110 to 300, and X represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, ##STR5## wherein R.sub.3, R.sub.4 and R.sub.5, which may be the same or different, each represent a hydrogen atom or a methyl group or (CH.sub.2)m.sub.2 COOM.sub.2, R.sub.6 represents a hydrogen atom, a methyl group, M.sub.1, M.sub.2 and Y, which may be the same or different, each represent a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, an alkylammonium or a substituted alkylammonium, m.sub.2 represents an integer of 0 to 2, with the compounds represented by the general formula (B) including acid anhydrides thereof, wherein the weight ratio of pigment to sulfite ranges from 1/10 to 10/1. ### Claim 2 (depends on 1) The aqueous ink as claimed in claim 1, wherein the copolymer is a copolymer of a polyalkylene glycol monoester monomer in which 110 to 300 mol of oxyalkylene groups having 2 carbon atoms are introduced, and an acrylic acid monomer. ### Claim 3 (depends on 1) The aqueous ink as claimed in claim 1, wherein said water-soluble solvent is a polyhydric alcohol. ### Claim 4 (depends on 1) The aqueous ink as claimed in claim 1, wherein said pigment/sulfite ratio ranges from 1/3 to 3/1. ### Claim 5 (depends on 1) The aqueous ink as claimed in claim 1, wherein the weight ratio of the pigment to the dispersant ranges from 1/10 to 10/1. ### Claim 6 (depends on 1) The aqueous ink as claimed in claim 1, wherein said aqueous ink is a pigmented ink for ink jet recording. ### Claim 7 (depends on 1) The aqueous ink as claimed in claim 1, which has a viscosity within the range of 1 to 10 cps. ### Claim 8 (depends on 1) The aqueous ink as claimed in claim 1, which has a surface tension within the range of 25 to 50 dyn/cm. ### Claim 9 (depends on 1) The aqueous ink as claimed in claim 1, which has dissolved oxygen content within the range of 0.012 to 0.016 ml/ml. ### Claim 10 (depends on 1) A method of ink jet recording, comprising: jetting the aqueous ink of claim 1 in droplet form from a nozzle to a recording medium by the action of thermal energy, thereby producing an image on the recording medium. ### Claim 11 (depends on 10) The method of claim 10, wherein said thermal energy is applied by a heat generating resistor element. ### Claim 12 An aqueous ink for ink jet recording, consisting essentially of: 1to 20% by weight of a pigment, 40 to 97.6% by weight of water, 1 to 20% by weight of water-soluble solvent, 0.1 to 10% by weight of a sulfite, 0.3 to 30% by weight of dispersant and 1 to 10% by weight of other components.