Abstract: An ink set includes a water-based ink and a water-based maintenance fluid. The water-based ink includes a colorant and at least one solvent whose SP value is 27.5 (MPa)(1/2) or higher in an amount of 30% by mass or more relative to a total mass of the solvents included in the water-based ink. The water-based maintenance fluid includes at least one solvent whose SP value is 25.0 (MPa)(1/2) or higher in an amount of 70% by mass or more relative to a total mass of the solvents included in the water-based maintenance fluid. A numerical value calculated by formula (1) is 1 or higher: a?b (1). a is a mass-weighted average of SP values (MPa)(1/2) of solvents included in the water-based ink, and b is a mass-weighted average of SP values (MPa)(1/2) of solvents included in the water-based maintenance fluid.

Abstract: There is provided a cleaning liquid usable for cleaning of an ink-jet recording apparatus, the cleaning liquid including: a first water-soluble organic solvent, a vapor pressure at 20° C. of the first water-soluble organic solvent being not less than 7 Pa; a second water-soluble organic solvent, a vapor pressure at 20° C. of the second water-soluble organic solvent being not more than 1 Pa; a nonionic surfactant; and water. The cleaning liquid satisfies the following conditions (1) to (3): Condition (1): 10?A+B?60; Condition (2): A/B?1; Condition (3): (A+B)/C?10. In the conditions (1) to (3), A: a content amount (% by mass) of the first water-soluble organic solvent, B: a content amount (% by mass) of the second water-soluble organic solvent, and C: a content amount (% by mass) of the nonionic surfactant.

Abstract: A cleaning liquid, usable for cleaning of an ink-jet recording apparatus, includes: a nonionic surfactant, solubility of the nonionic surfactant in water at 20° C. being less than 0.2% by mass; a first water-soluble organic solvent of which solubility parameter is not less than 13; a second water-soluble organic solvent of which solubility parameter is less than 12; and water. The cleaning liquid satisfies the following conditions (1) to (4): X?0.1;??Condition (1): A?B?0;??Condition (2): B/X?15;??Condition (3): 10?A+B?60.??Condition (4): X: a content amount (% by mass) of the nonionic surfactant, A: a content amount (% by mass) of the first water-soluble organic solvent, and B: a content amount (% by mass) of the second water-soluble organic solvent.

Abstract: There is provided a cleaning liquid usable for cleaning of an ink-jet recording apparatus, the cleaning liquid including: a first water-soluble organic solvent, a vapor pressure at 20° C. of the first water-soluble organic solvent being not less than 7 Pa; a second water-soluble organic solvent, a vapor pressure at 20° C. of the second water-soluble organic solvent being not more than 1 Pa; a nonionic surfactant; and water. The cleaning liquid satisfies the following conditions (1) to (3): Condition (1): 10?A+B?60; Condition (2): A/B?1; Condition (3): (A+B)/C?10. In the conditions (1) to (3), A: a content amount (% by mass) of the first water-soluble organic solvent, B: a content amount (% by mass) of the second water-soluble organic solvent, and C: a content amount (% by mass) of the nonionic surfactant.

Abstract: A water-based ink for ink-jet recording includes: a liquid component which is liquid at 20° C.; and a solid component which is solid at 20° C. The liquid component includes: a first water-soluble organic solvent of which vapor pressure at 20° C. is not less than 7 Pa; a second water-soluble organic solvent of which vapor pressure at 20° C. is not more than 1 Pa; and water. The solid component includes at least one resin selected from the group consisting of: acrylic acid-based resin, maleate ester-based resin, vinyl acetate-based resin, carbonate-based resin, styrene-based resin, ethylene-based resin, propylene-based resin, urethane-based resin, vinyl chloride-based resin and copolymer resin thereof.

Abstract: A water-based ink for ink-jet recording includes: a water-soluble organic solvent; water; and a surfactant having solubility in the water at 20° C. in a range of 0.05% by mass to 0.2% by mass, a content amount of the surfactant in an entire amount of the water-based ink being not less than 1% by mass.

Abstract: An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate group-modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains a monovalent metal ion, water, and a water-soluble organic solvent.

Abstract: An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate-group modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains an aggregating agent, water, and a water-soluble organic solvent. A dynamic surface tension of the water-based ink, measured under the condition where a life time is about 50 ms, is in the range of 35 mN/m to 45 mN/m. A dynamic surface tension of the treatment liquid, measured under the condition where a life time is about 50 ms, is in the range of 33 mN/m to 45 mN/m.

Abstract: A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one of a reducing sugar and a sugar alcohol and a calcium ion.

Abstract: A water-based ink for inkjet recording exhibits a blue color defined as L*<45, 25<C*<28, 255<h<278, and comprises a mixture of dyes and pigments, glycerol and polyethylene glycol #200 as water-soluble organic solvents and a polymeric dispersant. The ink will preferably have a ratio of glycerol to polyethylene glycol 200 within the range of from 2:1 to 3.5 1. The water-based ink preferably includes C.I. Pigment Blue 60 as a colorant and provides good printing stability and good storage stability. Tests show the inks to have good jettability.

Abstract: A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one selected from the group consisting of boric acid, diglycolic acid, and a chelating agent.

Abstract: An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate group-modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains a monovalent metal ion, water, and a water-soluble organic solvent.

Abstract: An ink set containing a water-based ink for ink jet recording and a treatment liquid. The water-based ink contains a phosphate-group modified self-dispersing pigment, water, and a water-soluble organic solvent. The treatment liquid contains an aggregating agent, water, and a water-soluble organic solvent. A dynamic surface tension of the water-based ink, measured under the condition where a life time is about 50 ms, is in the range of 35 mN/m to 45 mN/m. A dynamic surface tension of the treatment liquid, measured under the condition where a life time is about 50 ms, is in the range of 33 mN/m to 45 mN/m.

Abstract: A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one of a reducing sugar and a sugar alcohol and a calcium ion.

Abstract: A water-based ink for ink jet recording, containing: a coloring agent; water; and a water-soluble organic solvent. The coloring agent contains a phosphate group-modified self-dispersing pigment. The water-based ink further contains at least one selected from the group consisting of boric acid, diglycolic acid, and a chelating agent.

Abstract: A water-based ink for inkjet recording exhibits a blue color defined as L*<45, 25<C*<28, 255<h<278, and comprises a mixture of dyes and pigments, specifically including C.I. Pigment Blue 60 and C.I. Acid Blue 90, with water and a water-soluble organic solvent. The blue ink provide an image which has good water resistance and high optical density.

Abstract: A water base ink for ink-jet recording contains a self-dispersible coloring agent, a propylene glycol ether, and a surfactant represented by the following general formula (3): R1—O—(CH2CH2O)n—SO3M??(3) wherein R1 represents an alkyl group having a number of carbon atoms of 12 to 15, M represents Na or triethanolamine, and n represents an integer of 2 to 4, and wherein the propylene glycol ether is dipropylene glycol propyl ether. The ink satisfies three requirements of i) the satisfactory initial introduction performance of the ink into an ink flow passage of a stacked type printer head, ii) the prevention of the occurrence of feathering, and iii) the prevention of the insufficient spread of the ink.

Abstract: A water-based ink for ink-jet recording enables the expression of sharp text and lines in high density black, and the formation of a high quality gradation image in which the graininess is reduced in a black image of medium to high lightness. The inks include a color ink (A) and a color ink (B) each of which independently has a lightness index L* according to the L* a* b* calorimetric system of about 60 or less. The color ink (A) and the color ink (B) satisfy the following expression (I): about 120°?|???| about ?240°??(I) wherein ? is the hue angle of the color ink (A) and ? is the hue angle of the color ink (B). The chroma C* of a hue obtained by the combination of the color ink (A) and the color ink (B) is about 30 or less.

Abstract: A water-based ink for inkjet recording exhibits a blue color defined as L*<45, 25<C*<28, 255<h<278, and comprises a mixture of dyes and pigments, glycerol and polyethylene glycol #200 as water-soluble organic solvents and a polymeric dispersant. The ink will preferably have a ratio of glycerol to polyethylene glycol 200 within the range of from 2:1 to 3.5 1. The water-based ink preferably includes C.I. Pigment Blue 60 as a colorant and provides good printing stability and good storage stability. Tests show the inks to have good jettability.

Abstract: A water-based ink for inkjet recording exhibits a blue color defined as L*<45, 25<C*<28, 255<h<278, and comprises a mixture of dyes and pigments, specifically including C.I. Pigment Blue 60 and C.I. Acid Blue 90, with water and a water-soluble organic solvent. The blue ink provide an image which has good water resistance and high optical density.