# US 5,700,317 A · Bleed control in ink-jet inks via aqueous phase separation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,700,317 A - Document ID: US5700317A - Status: Granted - Kind: A - Application number: 08/641,995 - Filed: 1996-04-25 - Granted: 1997-12-23 - Earliest claimed: 1996-04-25 - Assignees: Hewlett-Packard Company - Inventors: Raymond J. Adamic - Web page: https://patentgrep.com/patent/US5700317A ## CPC - C09D 11/40: Ink-sets specially adapted for multi-colour inkjet printing - 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 Aqueous phase separation is employed to reduce or substantially eliminate bleed between adjacently-printed ink-jet ink compositions. An ink-jet ink set is provided that comprises first and second ink-jet inks, both of which comprise a colorant and an aqueous vehicle. The vehicle of the first ink-jet ink includes a polymer, while the vehicle of the second ink-jet includes a second species capable of inducing aqueous phase separation between the first and second inks in the event of contact therebetween. The resulting aqueous phases are separated by an interfacial boundary that serves to inhibit bleed between the inks. Importantly, in spite of the polymer concentration contained therein, the inks in the ink-jet ink set have sufficiently low viscosities such that they are capable of being readily jetted from an ink-jet pen. The use of aqueous phase separation to achieve bleed control is advantageous because it offers more flexibility in ink formulation, does not introduce highly toxic or corrosive components to the ink-jet ink composition, does not sacrifice edge acuity, and is an easily implemented and cost-effective manner in which to achieve bleed control in ink-jet printing. ## Claims ### Claim 1 An ink-jet ink set for ink-jet priming including a first ink-jet ink comprising a first colorant and a first aqueous vehicle and a second ink-jet ink comprising a second colorant and a second aqueous vehicle, said first aqueous vehicle including a first polymer and said second aqueous vehicle including a second species capable of inducing aqueous phase separation of said first and second aqueous vehicles in the event of contact therebetween, said first and second ink-jet inks having sufficiently low viscosities such that said first and second ink-jet inks are capable of being readily jetted from an ink-jet pen. ### Claim 2 (depends on 1) The ink-jet ink set of claim 1 wherein said first polymer has a molecular weight within the range of about 300 to 20,000. ### Claim 3 (depends on 2) The ink-jet ink set of claim 2 wherein said first polymer has a molecular weight within the range of about 1,000 to 5,000. ### Claim 4 (depends on 1) The ink-jet ink set of claim 1 wherein said first polymer is selected from the group consisting of polyethylene glycols having an average molecular weight of at least about 200; polypropylene glycols having an average molecular weight of at least about 200; polysaccharides; polysucrose having an average molecular weight within the range of about 40,000 to 400,000; ethoxylated glycerols having an average molecular weight within the range of about 500 to 10,000; propoxylated glycerols having an average molecular weight within the range of about 500 to 10,000; polyvinylalcohols having an average molecular weight within the range of about 10,000 to 200,000; polyvinylpyrrolidones having an average molecular weight within the range of about 2,000 to 500,000; polysaccharide salts; polyacrylamides having an average molecular weight within the range of about 1,000 to 1,000,000; polyacrylic acids having an average molecular weight within the range of about 1,000 to 500,000; polyethylenimines having an average molecular weight within the range of about 1,000 to 50,000; and derivatives thereof. ### Claim 5 (depends on 1) The ink-jet ink set of claim 1 wherein said second species is selected from the group consisting of a second polymer and a low-molecular weight component, wherein said second polymer is not identical to said first polymer. ### Claim 6 (depends on 5) The ink-jet ink set of claim 5 wherein said second polymer is selected from the group consisting of polyethylene glycols having an average molecular weight of at least about 200; polypropylene glycols having an average molecular weight of at least about 200; polysaccharides; polysucrose having an average molecular weight within the range of about 40,000 to 400,000; ethoxylated glycerols having an average molecular weight within the range of about 500 to 10,000; propoxylated glycerols having an average molecular weight within the range of about 500 to 10,000; polyvinylalcohols having an average molecular weight within the range of about 10,000 to 200,000; polyvinylpyrrolidones having an average molecular weight within the range of about 2,000 to 500,000; polysaccharide salts; polyacrylamides having an average molecular weight within the range of about 1,000 to 1,000,000; polyacrylic acids having an average molecular weight within the range of about 1,000 to 500,000; polyethylenimines having an average molecular weight within the range of about 1,000 to 50,000; and derivatives thereof. ### Claim 7 (depends on 5) The ink-jet ink set of claim 5 wherein said low-molecular weight component is selected from the group consisting of phosphate salts, sulfate salts, propyl alcohol, glycerol, ethylene glycol monobutyl ether, glucose, glycol, and sodium chloride. ### Claim 8 (depends on 7) The ink-jet ink set of claim 7 wherein said low-molecular weight component is selected from the group consisting of potassium phosphate and glycol. ### Claim 9 (depends on 1) The ink-jet ink set of claim 1 wherein said first polymer and said second species are each nonionic polymers. ### Claim 10 (depends on 9) The ink-jet ink set of claim 9 wherein said first polymer is polyethylene glycol and said second species is selected from the group consisting of ethoxylated glycerol, polyethylene glycol, polyvinyl pyrrolidone, and dextran, said dextran having an average molecular weight within the range of about 11,000 to 19,000. ### Claim 11 (depends on 10) The ink-jet ink set of claim 10 wherein said polyethylene glycol has an average molecular weight within the range of about 1,500 to 5,000. ### Claim 12 (depends on 1) The ink-jet ink set of claim 1 wherein said first ink-jet ink comprises (a) about 2 to 3 wt % dye; (b) about 5 to 15 wt % 1,5-pentanediol; (c) about 5 to 15 wt % 2-pyrrolidone; (d) about 5 to 25 wt % of said first polymer; and (e) water, and wherein said second ink-jet ink comprises (a) about 2 to 3 wt % dye; (b) about 7 to 15 wt % 1,5-pentanediol; (c) about 5 to 15 wt % 2-pyrrolidone; (d) about 5 to 25 wt % of said second species; and (e) water. ### Claim 13 (depends on 1) The ink-jet ink set of claim 1 wherein said first ink and said second ink each have a viscosity within the range of about 2 to 15 cP. ### Claim 14 (depends on 1) The ink-jet ink set of claim 1 wherein said first ink-jet ink is a yellow ink-jet ink, wherein said second ink-jet ink is a cyan ink-jet ink, wherein said ink-jet ink set further includes a third magenta ink-jet ink and a fourth black ink-jet ink, wherein said third magenta ink-jet ink and said fourth black ink-jet ink respectively contain a third species and a fourth species such that aqueous phase separation is induced in the event of contact between any ink in said ink-jet ink set. ### Claim 15 (depends on 14) The ink-jet ink set of claim 14 wherein said first polymer is polyethylene glycol having an average molecular weight of about 4000, wherein said second species comprises polyethylene glycol having an average molecular weight of about 7500 and polyethylene glycol having an average molecular weight of about 4000, and wherein said third species is polyethylene glycol methyl ether 2000. ### Claim 16 A method of reducing bleed in printing at least two different color inks onto a print medium from an ink-jet pen, said method comprising the steps of: (a) printing a first ink-jet ink comprising a first colorant and a first aqueous vehicle, said first aqueous vehicle including a first polymer; and (b) printing a second ink-jet ink comprising a second colorant and a second aqueous vehicle, said second aqueous vehicle including a second species capable of inducing aqueous phase separation of said first and second aqueous vehicles in the event of contact therebetween, said first and second ink-jet inks having sufficiently low viscosities such that said first and second ink-jet inks are capable of being readily jetted from an ink-jet pen, whereby bleed between said first ink and said second ink is reduced when said second ink is printed adjacent said first ink-jet ink. ### Claim 17 (depends on 16) The method of claim 16 wherein said first polymer has a molecular weight within the range of about 300 to 20,000. ### Claim 18 (depends on 17) The method of claim 17 wherein said first polymer has a molecular weight within the range of about 1,000 to 5,000. ### Claim 19 (depends on 16) The method of claim 16 wherein said first polymer is selected from the group consisting of polyethylene glycols having an average molecular weight of at least about 200; polypropylene glycols having an average molecular weight of at least about 200; polysaccharides; polysucrose having an average molecular weight within the range of about 40,000 to 400,000; ethoxylated glycerols having an average molecular weight within the range of about 500 to 10,000; propoxylated glycerols having an average molecular weight within the range of about 500 to 10,000; polyvinylalcohols having an average molecular weight within the range of about 10,000 to 200,000; polyvinylpyrrolidones having an average molecular weight within the range of about 2,000 to 500,000; polysaccharide salts; polyacrylamides having an average molecular weight within the range of about 1,000 to 1,000,000; polyacrylic acids having an average molecular weight within the range of about 1,000 to 500,000; polyethylenimines having an average molecular weight within the range of about 1,000 to 50,000; and derivatives thereof. ### Claim 20 (depends on 16) The method of claim 16 wherein said second species is selected from the group consisting of a second polymer and a low-molecular weight component. ### Claim 21 (depends on 20) The method of claim 20 wherein said second polymer is selected from the group consisting of polyethylene glycols having an average molecular weight of at least about 200; polypropylene glycols having an average molecular weight of at least about 200; polysaccharides; polysucrose having an average molecular weight within the range of about 40,000 to 400,000; ethoxylated glycerols having an average molecular weight within the range of about 500 to 10,000; propoxylated glycerols having an average molecular weight within the range of about 500 to 10,000; polyvinylalcohols having an average molecular weight within the range of about 10,000 to 200,000; polyvinylpyrrolidones having an average molecular weight within the range of about 2,000 to 500,000; polysaccharide salts; polyacrylamides having an average molecular weight within the range of about 1,000 to 1,000,000; polyacrylic acids having an average molecular weight within the range of about 1,000 to 500,000; polyethylenimines having an average molecular weight within the range of about 1,000 to 50,000; and derivatives thereof. ### Claim 22 (depends on 20) The method of claim 20 wherein said low-molecular weight component is selected from the group consisting of phosphate salts, sulfate salts, propyl alcohol, glycerol, ethylene glycol monobutyl ether, glucose, glycol, and sodium chloride. ### Claim 23 (depends on 22) The method of claim 22 wherein said low-molecular weight component is selected from the group consisting of potassium phosphate and glycol. ### Claim 24 (depends on 16) The method of claim 16 wherein said first polymer and said second species are each nonionic polymers. ### Claim 25 (depends on 24) The method of claim 24 wherein said first polymer is polyethylene glycol and said second species is selected from the group consisting of ethoxylated glycerol, polyethylene glycol, polyvinyl pyrrolidone, and dextran, said dextran having an average molecular weight within the range of about 11,000 to 19,000. ### Claim 26 (depends on 25) The method of claim 25 wherein said polyethylene glycol has an average molecular weight within the range of about 1,500 to 5,000. ### Claim 27 (depends on 16) The method of claim 16 wherein said first ink-jet ink comprises (a) about 2 to 3 wt % dye; (b) about 7 to 15 wt % 1,5-pentanediol; (c) about 5 to 15 wt % 2-pyrrolidone; (d) about 5 to 25 wt % of said first polymer; and (e) water, and wherein said second ink-jet ink comprises (a) about 2 to 3 wt % dye; (b) about 7 to 15 wt % 1,5-pentanediol; (c) about 5 to 15 wt % 2-pyrrolidone; (d) about 5 to 25 wt % of said second species; and (e) water. ### Claim 28 (depends on 16) The method of claim 16 wherein said first ink and said second ink have a viscosity within the range of about 2 to 15 cP. ### Claim 29 (depends on 16) The method of claim 16 wherein said first ink-jet ink is a yellow ink-jet ink, wherein said second ink-jet ink is a cyan ink-jet ink, wherein said method further comprises printing a third magenta ink-jet ink and a fourth black ink-jet ink, wherein said third magenta ink-jet ink and said fourth black ink-jet ink respectively contain a third species and a fourth species such that aqueous phase separation is induced in the event of contact between any of said first, second, third and fourth ink-jet inks. ### Claim 30 (depends on 29) The method of claim 29 wherein said first polymer is polyethylene glycol having an average molecular weight of about 4000, wherein said second species comprises polyethylene glycol having an average molecular weight of about 7500 and polyethylene glycol having an average molecular weight of about 4000, and wherein said third species is polyethylene glycol methyl ether 2000.