IP Library › Granted Patent US 7,278,726
Granted Patent B2
US 7,278,726 · App. 10/480,801 · Granted Oct 9, 2007

Ink jet recording ink set

Assignee: Ricoh Company, Ltd.
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Quick Facts
Patent No.
US 7,278,726
App. No.
10/480,801
Granted
Oct 9, 2007
Kind
B2
Abstract

Disclosed is an ink set for use in an ink jet recording process, wherein at least two aqueous inks A and B having different hues are superimposed to form a color image. The ink set can give a clear color image by high speed printing having good resolution without bleeding in the boundaries between two colors. Disclosed also are a method, an ink cartridge and an apparatus for ink jet recording using the above ink set. The ink set is characterized in that, of the two aqueous inks A and B, one ink A includes a coloring material A having an anionic group and in that the other ink B includes a coloring material B and a quaternary ammonium salt having at least one alkyl group which has 6 or less carbon atoms and which has a hydroxyl group.

Claims (19)

1. An ink set for use in an ink jet recording process wherein at least two aqueous inks A and B having different hues are superimposed to form a color image, characterized in that, of the two aqueous inks A and B, one ink A comprises a coloring material A having an anionic group and in that the other ink B comprises a coloring material B and a quaternary ammonium salt having at least one alkyl group which has 6 or less carbon atoms and which has a hydroxyl group,

wherein said quaternary ammonium salt is represented by the following general formula (II), (III) or (IV):

wherein X− represents a counter ion,

wherein X− represents a counter ion,

wherein X− represents a counter ion.

2. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said ink A is a black ink containing a self-dispersion type pigment comprising anion group-bearing carbon, in that said ink B is a color ink selected from the group consisting of an yellow ink, an cyan ink and a magenta ink.

3. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said ink A is a color ink selected from the group consisting of an yellow ink, an cyan ink and a magenta ink, and in that said coloring material A contained in said ink A is a self-dispersion type pigment having an anionic group.

4. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said coloring material B contained in said ink B is a water-insoluble coloring material, and in that said ink B comprises a polymer dispersing agent.

5. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said coloring material B contained in said ink B is a water-insoluble coloring material, and in that said ink B comprises a surfactant dispersing agent.

6. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said coloring material B is a dye having a carboxylic acid group and/or a sulfonic acid group.

7. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said coloring material B comprises fine particles colored with a dye or a pigment.

8. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said ink A and/or B comprises at least one water-soluble organic solvent selected from the group consisting of glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, tetraethylene glycol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, polyethylene glycol, 1,2,4-butanetriol, 1,2,6-hexanetriol, thiodiglycol, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone.

9. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said ink A and/or B comprise at least one surfactant selected from the group consisting of acetylene glycol surfactants, polyoxyethylene alkyl ether surfactants, polyoxyethylene alkylphenyl ether surfactants and fluorine-containing surfactants.

10. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said ink A and/or B comprise an acetylene glycol surfactant having 6 or more carbon atoms in the main chain thereof, and a polyoxyethylene phenyl ether having a polyoxyethylene moiety having a polymerization degree of 5 to 12.

11. An ink set for use in an ink jet recording process as recited in claim 1 , wherein said ink A and/or B have a pH of 6 to 11.

12. An ink jet recording method wherein an ink set comprising at least two aqueous inks A and B having different hues is used to form a color image and wherein said at least two aqueous inks A and B are superimposed on a recording medium to form an image thereon, wherein said ink set used is an ink set according to claim 1 .

13. An ink jet recording method as recited in claim 12 , wherein said recording medium has a Stockigt sizing degree of 3 or more seconds.

14. An ink cartridge for ink jet recording, comprising ink containers containing an ink set, wherein said ink set is an ink set according to claim 1 .

15. An ink jet recording apparatus comprising ink containers or an ink cartridge containing an ink set, wherein said ink set is an ink set according to claim 1 .

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 12, 2004
From: NAGAI, KIYOFUMI
To: RICOH COMPANY, LTD.
Reel/Frame 015203/0726 →
Priority Claims (1)
JP 2001-185111 · Jun 19, 2001 · national
Continuity (1)
Related Publication 20040155946A1 · Aug 12, 2004