Abstract: A cyan ink comprising a phthalocyanine derivative represented by the following formula (I), excellent in color reproducibility, suitable for use in the ink jet recording method is disclosed. The combination use of this cyan ink comprising the phthalocyanine derivative with yellow and magenta inks, each comprising a specific dye, gives excellent color printing. ##STR1## wherein X represents an ion of a metal selected from Cu, Fe, Co and Ni, R.sup.1 represents H or an alyl group, Z represents --O, --COOH or NR.sup.2 R.sup.3 (where R.sup.2 represents H or an alkyl group, and R.sup.3 represents an alkyl group or phenyl group), n represents an integer of 1 to 15, k and l represent 0 or 1, and m represents an integer of 1 to 4, provided that k, l and m fulfill the inequality 2.ltoreq.k+1+m.ltoreq.4.

Abstract: An ink jet recording film is provided which has well-balanced properties required of the ink jet recording film. The ink jet recording film comprises a transparent substrate, an anchor coat layer laminated on one side of the substrate, and an ink-receptive layer laminated on the anchor coat layer; wherein the ink-receptive layer comprises a polyvinyl alcohol having a degree of saponification of 80 to 95% and a degree of polymerization of 1,000 to 2,000.

Abstract: An ink composition is provided which enables high-quality recording on plain paper and can record an image having excellent water resistance. The ink composition comprises a dye represented by the following formula (I): ##STR1## wherein M represents an unsubstituted or substituted ammonium, R.sup.1 represents COOM, R.sup.2 represents --P(=O)n--(OM).sub.2, where n is 0 or 1, R.sup.3 represents SO.sub.3 M, R.sup.4 and R.sup.5 independently represent H, an alkyl group, or an alkoxyl group, R.sup.6 represents H, a phenyl group which may be substituted, an alkylcarbonyl group, or an alkyl group which may be substituted with a hydroxyl or alkoxyl group, and m is 0 or 1.

Abstract: An ink-jet printing ink composition which has high printing stability after long periods of time and at high temperatures is provided. The ink-jet printing ink composition is an aqueous ink having a nitrite ion concentration between about 0.2 to 10 parts per million (ppm) in order to lower the concentration of dissolved gas in the ink.

Abstract: A liquid ink composition having a sodium ion concentration between about 0.001 and 0.2% by weight or ink tank formed of resin or synthetic rubber containing between about 10 and 100 ppm of fatty acid or fatty acid derivatives is provided. The liquid composition is useful in every ink tank formed of resin or synthetic rubber containing fatty acid or the derivatives. The ink tank is also useful in despite of sodium ion concentration of ink. Formation of insoluble substances produced to react with sodium ion and fatty acid or the derivatives deteriorates the ink flow to clog the filter in the pass. The low sodium ion concentration of ink, or the low fatty acid or the derivatives concentrations of tank material prevents from forming the insoluble substances.

Abstract: A liquid ink composition having a sodium ion concentration between about 0.001 and 0.2% by weight or ink tank formed of resin or synthetic rubber containing between about 10 and 100 ppm of fatty acid or fatty acid derivatives is provided. The liquid composition is useful in every ink tank formed of resin or synthetic rubber containing fatty acid or the derivatives. The ink tank is also useful in despite of sodium ion concentration of ink. Formation of insoluble substances produced to react with sodium ion and fatty acid or the derivatives deteriorates the ink flow to clog the filter in the pass. The low sodium ion concentration of ink, or the low fatty acid or the derivatives concentrations of tank material prevents from forming the insoluble substances.

Abstract: An oxygen absorbing capsule containing an oxygen absorbing material for use in an ink jet printing device is provided. The capsule wall is formed of a resinous material insoluble in the ink composition, but having a large permeability to gases so that oxgyen may be absorbed from the solution. The oxygen absorbing material is preferably an aqueous solution of a salt of pyrogallol. The capsule may be positioned in an ink tank, an ink supply tube or in an ink ejection head of an ink jet recording device for absorbing oxygen from the ink composition. Stable printing, free from nozzle clogging, can thus be carried out for extended intervals of time.

Abstract: An aqueous fluid ink particularly well suited for use in an ink jet printer is provided. The aqueous fluid ink compositions include a humectant in combination with urea for efficiently lowering the freezing point without a significant increase in viscosity. Aqueous fluid ink compositions prepared in accordance with the invention include at least one humectant selected from the group consisting of aliphatic polyhydric alcohols, alkyl ether derivatives of the aliphatic polyhydric alcohols and acetate ester derivatives of the aliphatic polyhydric alcohols, urea, a water-soluble dye and water. Viscosity is maintained between about 2 and 3 centipoises at 20.degree. C. and a quick drying ink is provided by adjusting the pH to between about 12 and 13.5.

Abstract: A liquid ink for printers including a component for dissolving at least one of a fibrous material, sizing material and surface treatment material included in the recording medium is provided. An aqueous liquid ink in accordance with the invention includes a water-soluble dye, a strong alkali material, at least one wetting agent and water. The pH of the ink is between about 10 and 14. Shelf life of the liquid ink is improved by including a preservative and the speed of ink penetration into the print paper can be increased by including a surface active agent.