# US 9,039,130 B2 · Ink composition and method for ink jet recording > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,039,130 B2 - Document ID: US9039130B2 - Status: Granted - Kind: B2 - Application number: 14/087,544 - Filed: 2013-11-22 - Published: 2014-12-11 - Granted: 2015-05-26 - Earliest claimed: 2012-11-26 - Assignees: Seiko Epson Corporation - Applicants: Seiko Epson Corporation - Inventors: Masahiro Yatake - Web page: https://patentgrep.com/patent/US9039130B2 ## CPC - C09D 11/30: Inkjet printing inks - B41J 2/01: Ink jet - B41J 2/2107: {characterised by the ink properties (supplying ink in a solid state B41J2/17593)} - C09D 11/106: containing macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds - 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 An ink composition for ink jet recording contains a polymer particle that has a core portion and a shell portion on a surface of the core portion. The core portion has a glass transition temperature of 0° C. or less, and the shell portion has a glass transition temperature of 20° C. or more. The difference between the glass transition temperature of the core portion and that of the shell portion is 30° C. or more. ## Claims ### Claim 1 An ink composition for ink jet recording comprising a polymer particle having a core portion and a shell portion on a surface of the core portion, the core portion having a glass transition temperature of 0° C. or less and the shell portion having a glass transition temperature of 20° C. or more, wherein a difference between the glass transition temperature of the core portion and the glass transition temperature of the shell portion is 30° C. or more, wherein: a mass ratio c/s is in a range of 0.4 to 4, where c and s are a mass of the core portion and the shell portion, respectively, of the polymer particle; and a relation (c/s)/φ≧0.01 is satisfied where φ is a particle diameter of the polymer particle in nm. ### Claim 2 (depends on 1) The ink composition for ink jet recording according to claim 1, wherein 80% by mass or more of all repeating units of the core portion of the polymer particle are derived from a hydrophobic monomer. ### Claim 3 (depends on 2) A method for ink jet recording comprising: (a) discharging a droplet of the ink composition for ink jet recording according to claim 2 from a recording head onto a recording medium; and (b) heating the recording medium. ### Claim 4 (depends on 1) The ink composition for ink jet recording according to claim 1, wherein 80% by mass or more of all repeating units of the shell portion of the polymer particle are derived from a hydrophilic monomer. ### Claim 5 (depends on 4) A method for ink jet recording comprising: (a) discharging a droplet of the ink composition for ink jet recording according to claim 4 from a recording head onto a recording medium; and (b) heating the recording medium. ### Claim 6 (depends on 1) The ink composition for ink jet recording according to claim 1, wherein 80% by mass or more of all repeating units of the shell portion of the polymer particle are composed of a repeating unit (A) derived from at least one selected from the group consisting of methyl (meth)acrylate and ethyl (meth)acrylate and a repeating unit (B) derived from (meth)acrylic acid. ### Claim 7 (depends on 6) A method for ink jet recording comprising: (a) discharging a droplet of the ink composition for ink jet recording according to claim 6 from a recording head onto a recording medium; and (b) heating the recording medium. ### Claim 8 (depends on 1) The ink composition for ink jet recording according to claim 1, wherein the shell portion of the polymer particle has a repeating unit (C) derived from at least one hydrophobic monomer selected from the group consisting of a monofunctional (meth)acrylate having an alkyl group containing 8 or more carbon atoms and a (meth)acrylate having a ring structure containing 4 or more carbon atoms. ### Claim 9 (depends on 8) The ink composition for ink jet recording according to claim 8, wherein the ring structure is an alicyclic or heterocyclic structure. ### Claim 10 (depends on 8) The ink composition for ink jet recording according to claim 8, wherein the repeating unit (C) constitutes 1% to 10% by mass of all repeating units of the shell portion of the polymer particle. ### Claim 11 (depends on 8) The ink composition for ink jet recording according to claim 8, wherein the shell portion of the polymer particle further has a repeating unit (D) derived from a (meth)acrylate having a polyalkylene glycol unit. ### Claim 12 (depends on 11) The ink composition for ink jet recording according to claim 11, wherein the repeating unit (D) constitutes 1% to 10% by mass of all repeating units of the shell portion of the polymer particle. ### Claim 13 (depends on 6) A method for ink jet recording comprising: (a) discharging a droplet of the ink composition for ink jet recording according to claim 6 from a recording head onto a recording medium; and (b) heating the recording medium. ### Claim 14 (depends on 1) The ink composition for ink jet recording according to claim 1, wherein the particle diameter of the polymer particle is in a range of 30 nm to 500 nm. ### Claim 15 (depends on 1) The ink composition for ink jet recording according to claim 1, wherein a gel fraction of the polymer particle is 10% or less as measured in tetrahydrofuran. ### Claim 16 (depends on 1) The ink composition for ink jet recording according to claim 1, wherein a polymer particle content is in a range of 0.5% to 20% by mass, both inclusive. ### Claim 17 (depends on 1) The ink composition for ink jet recording according to claim 1, wherein an emulsifier content of the ink is 0.01% by mass or less. ### Claim 18 (depends on 1) A method for ink jet recording comprising: (a) discharging a droplet of the ink composition for ink jet recording according to claim 1 from a recording head onto a recording medium; and (b) heating the recording medium. ### Claim 19 (depends on 1) A method for ink jet recording comprising: (a) discharging a droplet of the ink composition for ink jet recording according to claim 1 from a recording head onto a recording medium; and (b) heating the recording medium.