# US 9,040,620 B2 · Process, dispersions and use > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,040,620 B2 - Document ID: US9040620B2 - Status: Granted - Kind: B2 - Application number: 13/120,869 - Filed: 2009-10-01 - Published: 2011-07-14 - Granted: 2015-05-26 - Earliest claimed: 2008-10-02 - Assignees: Fujifilm Imaging Colorant Limited - Applicants: Tom Annable; Mark Holbrook; Neil Anthony Tallant; John Patrick O'Donnell - Inventors: Tom Annable; Mark Holbrook; Neil Anthony Tallant; John Patrick O'Donnell - Web page: https://patentgrep.com/patent/US9040620B2 ## CPC - C09D 11/322: Pigment inks - C08K 5/1515: Three-membered rings - C09B 67/0013: {with polymeric coatings} - C09B 67/009: {polymeric dispersing agent} - C09B 67/0096: {Purification; Precipitation; Filtration} - C09B 67/0097: {Dye preparations of special physical nature; Tablets, films, extrusion, microcapsules, sheets, pads, bags with dyes} - 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) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - C09B: ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES {, e.g. PIGMENTS}; MORDANTS; LAKES (fermentation or enzyme using processes to synthesise a desired chemical compound C12P) ## Abstract A process for preparing an encapsulated pigment dispersion suitable for use in an ink jet printing ink comprising the following steps in the order I) followed by II): I) providing a dispersion comprising a pigment, a liquid medium and a dispersant comprising the repeat units from copolymerizing the ethylenically unsaturated monomers in components a) to c): a) from 75 to 97 parts of one or more hydrophobic ethylenically unsaturated monomers comprising at least 50 parts benzyl (meth)acrylate; b) from 3 to 25 parts one or more hydrophilic ethylenically unsaturated monomers having one or more ionic group(s); c) from 0 to 2 parts of one or more hydrophilic ethylenically unsaturated monomers having a hydrophilic non-ionic group; and wherein the parts are by weight and the sum of the parts a) to c) add up to 100; II) cross-linking the dispersant in the presence of the pigment and the liquid medium. ## Claims ### Claim 1 A process for preparing an encapsulated pigment dispersion suitable for use in an ink jet printing ink comprising the following steps in the order I) followed by II): I) providing a dispersion comprising a pigment, a liquid medium and a dispersant comprising the repeat units from copolymerising the ethylenically unsaturated monomers in components a) to c): a) from 75 to 97 parts of one or more hydrophobic ethylenically unsaturated monomers having a calculated log P of at least 1 and comprising at least 50 parts benzyl (meth)acrylate; b) from 3 to 25 parts one or more hydrophilic ethylenically unsaturated monomers having a calculated log P of less than 1 and having one or more ionic group(s); c) from 0 to 2 parts of one or more hydrophilic ethylenically unsaturated monomers having a hydrophilic non-ionic group selected from the group consisting of polyethyleneoxy, polyacrylamide, polyvinyl pyrrolidone, hydroxy functional celluloses and poly vinyl alcohol; and wherein the parts are by weight and the sum of the parts a) to c) add up to 100; II) cross-linking the dispersant in the presence of the pigment and the liquid medium with trimethylolpropane polyglycidyl ether such that the cross-linking reaction links the dispersant molecules by covalent bonds, wherein the dispersant has 0.9 to 2.65 mmoles of ionic groups per g of dispersant. ### Claim 2 (depends on 1) A process according to claim 1 wherein component a) comprises at least 60 parts of benzyl (meth)acrylate. ### Claim 3 (depends on 1) A process according to claim 1 wherein component a) comprises at least 70 parts of benzyl (meth)acrylate. ### Claim 4 (depends on 1) A process according to claim 1 wherein component a) consists of benzyl (meth)acrylate. ### Claim 5 (depends on 1) A process according to claim 1 wherein component b) comprises methacrylic acid. ### Claim 6 (depends on 1) A process according to claim 1 wherein component b) is methacrylic acid. ### Claim 7 (depends on 1) A process according to claim 1 wherein component c) is not present. ### Claim 8 (depends on 1) A process according to claim 1 wherein the dispersant comprises the repeat units from copolymerising the ethylenically unsaturated monomers in components a) to c): (a) from 80 to 93 parts of one or more hydrophobic monomers having a calculated log P of at least 1 and comprising at least 50 parts benzyl (meth)acrylate; (b) from 7 to 20 parts of methacrylic acid; (c) 0 parts of hydrophilic ethylenically unsaturated monomers having a hydrophilic non-ionic group selected from the group consisting of polyethyleneoxy, polyacrylamide, polyvinyl pyrrolidone, hydroxy functional celluloses and poly vinyl alcohol, wherein the parts are by weight and the sum of the parts a) to c) add up to 100. ### Claim 9 (depends on 1) A process according to claim 1 wherein component b) comprises one or more monomers having one or more carboxylic acid groups. ### Claim 10 (depends on 1) A process according to claim 1 wherein the liquid medium comprises water. ### Claim 11 (depends on 1) A process according to claim 1 wherein the dispersion provided in step I) has a sodium chloride critical coagulation concentration of no more than 2.0M. ### Claim 12 (depends on 1) A process according to claim 1 wherein the resulting encapsulated pigment dispersion has a sodium chloride critical coagulation concentration of no more than 2.0M. ### Claim 13 (depends on 12) A process according to claim 12 wherein the resulting encapsulated pigment dispersion has a sodium chloride critical coagulation concentration of from 0.2M to 1.6M. ### Claim 14 (depends on 1) A process according to claim 1 further comprising the step of purifying the encapsulated pigment dispersion. ### Claim 15 (depends on 1) A process according to claim 1 further comprising adding one or more additives selected from the group consisting of viscosity modifiers, pH buffers, metal chelating agents, surfactants, corrosion inhibitors, biocides, dyes, water-miscible organic solvent(s) and kogation reducing additives. ### Claim 16 (depends on 1, 8) An encapsulated pigment dispersion obtained by a process according to claim 1 or claim 8. ### Claim 17 (depends on 16) An ink jet printing ink comprising an encapsulated pigment dispersion according to claim 16. ### Claim 18 (depends on 17) An ink jet printer cartridge comprising a chamber and an ink jet printing ink according to claim 17, wherein the ink jet printing ink is present in the chamber. ### Claim 19 (depends on 1) A process according to claim 1 wherein the trimethylolpropane polyglycidyl ether has a weight per epoxy group of 140. ### Claim 20 (depends on 1) A process according to claim 1 wherein the cross-linking is performed in the presence of a borate salt and/or boric acid. ### Claim 21 (depends on 1) A process according to claim 1 wherein the dispersant is free from hydrophilic ethylenically unsaturated monomers having one or more hydrophilic non-ionic groups. ### Claim 22 (depends on 1) A process according to claim 1 wherein the hydrophobic ethylenically unsaturated monomers having a calculated log P of at least 1 consist of benzyl (meth)acrylate and the dispersant is free from hydrophilic ethylenically unsaturated monomers having one or more hydrophilic non-ionic groups. ### Claim 23 (depends on 1) A process according to claim 1 wherein component b) consists of one or more monomers having one or more carboxylic acid groups. ### Claim 24 (depends on 1) A process according to claim 1 wherein the liquid medium consists of water.