Ink for an ink-jet printer of the present invention includes polyester particles colored with a colorant which are dispersed in an aqueous medium.

Ink compositions comprising an aqueous medium containing: (1) at least one water-soluble dye; (2) at least one cyclic ester or amide of the formula: ##STR1## wherein m is a whole number from 3 to 5 and X represents --O-- or --N(R)-- in which R represents hydrogen, alkyl or substituted alkyl; (3) at least one hydroxy compound selected from polyhydroxy compounds having at least four hydroxy groups, optionally substituted cycloalkanols, cyclohexane dimethanol, benzyl alcohol, benzene dimethanol, ph...

A cyan ink applicable to an ink set has plurality of aqueous inks each containing at least: water; a water-insoluble coloring material; and plurality of water-soluble organic solvents including a good medium or good mediums for the water-insoluble coloring material and a poor medium or poor mediums for the water-insoluble coloring material. A ratio of a poor medium to a good medium in the cyan ink is in a specific range. A water-soluble organic solvent showing the maximum Ka value out of respect...

The present invention pertains to a yellow ink for inkjet printing and, in particular, to a yellow ink comprising a combination of specific yellow colorants. The present invention further pertains to an ink set comprising this yellow ink. The ink and ink set are particularly advantageous for printing on plain paper.

It is an object of the present invention to provide an ink jet recording ink with excellent storage stability, with which no mold or other microbes will be generated over an extended period. The ink jet recording ink of the present invention contains water and a colorant comprising a pigment encapsulated by a polymer having a carboxyl group, wherein this ink jet recording ink is characterized by containing at least methylisothiazolone and octylisothiazolone.

An ink obtained by dissolving at least one specific dye in an aqueous medium, wherein the dyes contained in the ink all have a solubility of 15 g or more in 100 g of water at 25.degree. C. under atmospheric pressure; and an ink set formed from the ink. The dye is preferably a dye having an oxidation potential of 1.0 V (vs SCE) or more, more preferably a specific azo dye having a heterocyclic group of a specific structure or an aromatic group which is bound directly to an azo group, or a specific...

An ink for ink-jet recording is provided in which a copper phthalocyanine dye is used and a thiazole-based compound is also used. In this ink, the mildew resistant properties are not impaired. Furthermore, the ink exhibits excellent ozone resistance, and the formation of a precipitate is prevented in the ink although the thiazole-based compound is used. In the ink for ink-jet recording containing the copper phthalocyanine dye and the thiazole-based compound, the used copper phthalocyanine dye ha...

An ink jet ink composition of water, a humectant, and a hyperbranched polymeric dye of a hyperbranched polymer having a dye chromophore pendant on the polymer chain or incorporated into the polymer backbone.

An ink composition for ink jet recording which is an oil in-water type dispersion prepared by dispersing, in an aqueous medium, a mixture of a hydrophobic dye solution and finely divided particles of vinyl polymer, wherein the vinyl polymer is essentially insoluble in water and does not swell in water but swells in solvents capable of dissolving hydrophobic dyes, said ink composition having a low viscosity, a high density and being very stable. The records obtained using this ink composition are...

An ink composition for ink jet recording consisting essentially of a water-soluble wetting agent, water, a water-soluble dye and an oxygen absorber.