Abstract: The present invention relates to a method for treating liquids used in inkjet recording comprising, providing a first printing liquid and a second printing liquid that is capable of reacting with the first printing liquid to cause coagulation and thickening if mixed with the first printing liquid, and exposing the first and second printing liquids to each other to form a mixture, wherein when the mixture includes a coagulation-thickening preventing agent which prevents the reaction of the printing liquids.

Abstract: The present invention is an ink set for ink-jet recording using at least two kinds of inks comprising a first ink containing at least a pigment, a water-soluble solvent and water, and a second ink containing at least a pigment, a coagulant, a water-soluble solvent and water and having the absolute value of ?-potential of not less than 10 mV. The present invention also provides an ink-jet recording method using the ink set for ink-jet recording, wherein an image is formed by applying the first ink and second ink on a recording medium so as to contact to each other. The present invention further provides an ink-jet recording apparatus comprising a recording head for ejecting at least the first ink and second ink.

Abstract: The present invention provides an ink set for ink jet recording, an ink jet recording method and an ink jet recording apparatus using the same. The ink set for ink jet recording includes a black ink and color inks including at least cyan, magenta and yellow inks. The black ink includes at least one coagulable agent, and one or more of the color inks is a coagulant-containing color ink containing a coagulant. The contact angle of each of the black ink and the color inks to a recording material is about 50° or less after 1 second of contact. The surface tension of each of the black ink and the color inks is about 40 mN/m or less. The difference between the surface tension of the black ink and that of the coagulant-containing color ink is about 5 mN/m or less.

Abstract: Ink jet recording method and apparatus is provided in which a color image is recorded by discharging, onto a recording medium, a black ink and at least one of a cyan ink, a magenta ink and a yellow ink from a black-ink recording head that ejects the black ink onto the recording medium, and a color-ink recording head that ejects the at least one of a cyan ink, a magenta ink and a yellow ink onto the recording medium, wherein the black ink contains carbon black, water, a water-soluble organic solvent, and a water-soluble polymer having an anionic functional group, and has a drying time of 5 seconds or more on the recording medium, and at least one type of the color ink contains a color material, water, a water-soluble organic solvent, and a coagulating agent, and has a drying time of 5 seconds or less on the recording medium.

Abstract: An ink set for ink jet recording including plural color inks including a black ink, the ink set including water, a water-soluble organic solvent and colorants. At least one of the color inks having a hue other than black is a specified color ink containing a compound for coagulating a colorant contained in the black ink, at least one of other color inks has a function for improving coagulability between the colorant contained in the black ink and the compound contained in the specified color ink, and the drying time of the black ink on a plain paper sheet is less than 5 seconds.

Abstract: Provided is magenta ink that satisfies all the necessary properties including good light-fastness, good color reproducibility, especially good color reproducibility of magenta-related secondary colors of red and blue, and high reliability, and gives satisfactory high-quality images. Also provided are a color ink set for ink-jet recording, which contains the magenta ink, and an ink-jet recording method in which is used the magenta ink or the color ink set. The magenta ink contains water, a colorant and at least two water-soluble organic solvents, and its visible-light absorbance spectrum gives a first peak A (abs.) within a range of from 500 to 570 nm and a second peak B (abs.) within a range of from 300 to 350 nm with a ratio A/B falling between 0.9 and 2.5. The magenta ink is combined with cyan ink and yellow ink to form the color ink set, which contains water, colorants and at least two water-soluble organic solvents.

Abstract: The present invention provides an ink-jet recording method and an ink-jet printer, which can diminish or control curling and cockling of the recording medium. The present invention also provides an ink-jet recording method and an ink-jet printer, which can form a recorded image of high quality, resistance to water and drying capacity, while diminishing or controlling curling and cockling. In the ink-jet recording method and ink-jet printer of the present invention, a recording image is formed on the surface of a recording medium containing at least one organic compound selected from the group consisting of 1,1,1-tris(hydroxylmethyl)propane, monosaccharides, oligosaccharides, and sugar alcohols, by applying an ink composed of at least a colorant, a water-soluble organic solvent, and water.

Abstract: Disclosed is an ink for ink jet recording comprising water, a pigment that is self-dispersible-in-water, and a water-soluble organic solvent, wherein said ink for ink jet recording contains a water-soluble organic compound having an S.P. value of 12 or less and a surface tension at 25° C. of less than 40 mN/m in an amount of from 3.0 to 15.0 wt % based on the entire weight of the ink. Also, disclosed are a method for producing the ink and an ink jet recording method by using the ink.

Abstract: Disclosed is an ink for ink jet recording comprising water, a pigment that is self-dispersible-in-water, and a water-soluble organic solvent, wherein said ink for ink jet recording contains a water-soluble organic compound having an S.P. value of 12 or less and a surface tension at 25° C. of less than 40 mN/m in an amount of from 3.0 to 15.0 wt % based on the entire weight of the ink. Also, disclosed are a method for producing the ink and an ink jet recording method by using the ink.

Abstract: A recording material is disclosed, comprising a colorless or pale solution containing an electrolyte, a water-soluble organic solvent and water, and an ink containing a pigment, an anionic compound, a water-soluble organic solvent and water, wherein the number of particles of 0.5 &mgr;m or more present in 1 L of the recording material is 1×1011 or more, and the number of particles of 5 &mgr;m or more is 1×109 or more. Also disclosed is an image forming method using the recording material.

Abstract: Disclosed is an ink jet recording ink comprising water, an aqueous organic solvent, a surfactant and a self-dispersible pigment, wherein the number average particle diameter of dispersed particles of the pigment is from 15 to 100 nm, given that mv is the volumetric average particle diameter of the dispersed particles of said pigment and mn is the number average diameter of the dispersed particles of said pigment, mv/mn is less than or equal to 3, the number of particles having a particle diameter greater than or equal to 0.5 .mu.m among the dispersed particles of the pigment contained in one liter of the ink is less than or equal to 7.5.times.10.sup.10, the surface tension of the ink is less than or equal to 60 mN/m, the electroconductivity of the ink is from 0.05 to 0.4 S/m and the pH of the ink is from 6 to 11. This ink provides a high storage stability and a uniform image having high water-resistance, resolution, and density can be obtained.

Abstract: The present invention provides an ink which provides an image with a sufficient image density free from bleeding and unevenness, dries rapidly on paper and can be jetted at a high reliability and a recording method using said ink. A novel ink for ink jet recording comprising water, a coloring material and a water-soluble organic solvent is provided, characterized in that said ink comprises a polymer containing a carboxyl group having an average molecular weight of from 1,000 to 20,000 in the free or salt state in an amount of from 0.1 to 3% by weight, a water-soluble organic compound which normally stays solid and vaporizes in a proportion of not less than 50% by weight at a temperature of from 100.degree. C. to 350.degree. C. in an amount of from 1 to 20% by weight, and a compound represented by the following formula (A):R--O--X.sub.n H (A)wherein R represents a functional group selected from the group consisting of C.sub.

Abstract: Ink for ink jet recording containing water, a coloring material and a water-soluble organic solvent, containing 0.01 to 5 wt % of a polymer containing a carboxylic group or polymer having salt of a carboxylic group, having an acid value of 50 to 700; and 0.001 to 5 wt % of a surface active agent, wherein the foaming surface viscosity of the ink is 0.05 to 1.0 g/s. The polymer is a copolymer of hydrophobic .alpha., .beta.- unsaturated ethylene monomer and a monomer having a plurality of hydrophilic --COOM groups (wherein M is hydrogen, alkali metal, or an onium compound including ammonium ion, organic ammonium ion, phosphonium ion, sulfonium ion, oxonium ion, stibonium ion, stanonium and iodonium), a monomer having acid anhydride thereof or a monomer containing ester thereof. The ink for ink jet recording and the ink jet recording method according to the present invention provide an image having a high optical density, without unevenness and free from feathering and bleeding.

Abstract: An ink for ink jet recording process, comprising water, a coloring material and a water-soluble organic solvent, wherein the ink further comprises a compound having a plurality of hydroxyl groups and at least one group selected from the group consisting of alkyl, haloalkyl, alkenyl, alkinyl, cycloalkyl and aromatic groups each having from 5 to 18 carbon atoms.

Abstract: An ink for ink jet recording comprising water, a colorant and a water-soluble organic solvent, in which the water-soluble organic solvent comprises 2,2'-thiodiethanol having a purity of not less than 96% by weight and an electrical conductivity of from not less than 5.0.times.10.sup.-4 S/m to not more than 5.0.times.10.sup.-2 S/m as determined in the form of 10 wt % aqueous solution.

Abstract: A novel ink for ink jet recording, comprising water, a coloring material, a high molecular surface active agent and a sulfur-containing alcohol; and an ink for ink jet recording method using the ink which causes neither nozzle clogging nor disturbance of jetting and can provide a high density uniform image that can be easily dried on ordinary paper.

Abstract: An ink for thermal ink jet recording comprising water, a coloring material, (a) 2,2'-thiodiethanol, and (b) C.sub.n H.sub.2n+1 O(CH.sub.2 CH.sub.2 O).sub.m H, wherein n represents an integer of 3 to 6 and m represents an integer of 1 to 3; and the content of the component (a) is 3 to 20% by weight based on the ink and the content of the component (b) is from 1 to 20% by weight based on the ink.

Abstract: An ink-jet ink contains water, a coloring material and an amine compound represented by the formula: R.sub.1 R.sub.2 R.sub.3 N (I) wherein one or two of R.sub.1, R.sub.2 and R.sub.3 represent(s) (an) alkyl group(s) having 1 to 5 carbon atoms substituted by at least one group selected from the group consisting of a carboxy group, a sulfonic acid group, and a Li, Na, Na, K or ammonium salt thereof, and the remainder represents(s) (an) hydrogen atom(s) or (an) alkyl group(s) having 1 to 5 carbon atoms substituted by a hydroxide group or a carbamoyl group. The pH value of the ink is preferably between 6 to 8. Moreover, printing may be made by applying thermal energy to the ink and forming droplets.The ink and the method of printing using the ink may prevent the change of the amount of ink droplets due to kogation on a heater even with a long-term use, and may not cause a heater trouble due to the corrosion of materials constantly in contact with ink.

Abstract: Ink-jet recording ink comprising water, a water-soluble organic solvent and a color material as essential ingredients, wherein the total volume of particulate matter ranges from 1.times.10.sup.-9 to 1.times.10.sup.-2 cm.sup.3 per cm.sup.3 of ink, whereby defects in images such as blank areas on images, fluctuations in dot diameter and the disturbed shape of dots are not generated to give a prominent effect and wherein the total volume of the particulate matter existing in 1 cm.sup.3 of the ink is adjusted to 3.5.times.10.sup.-6 or less, whereby ink which is stable even after long-term use can be obtained and change in amount of ink at jetting is slight, as well as defects in images can be prevented.

Abstract: An ink for inkjet printers comprises water, a water-soluble organic solvent, and a colorant. The ink further comprises an amine having at least one substituent selected from the group consisting of a sulfonic acid group, a carboxylic acid group and a halogen atom, so that the variation in pH of the ink can be suppressed to a minimum. The pH of the ink is preferably in the range of from 5 to 9.