Abstract: Disclosed herein is an ink comprising a first pigment, a second pigment and a dispersant, both of the pigment being dispersed in an aqueous medium, wherein the first pigment is a self-dispersing pigment having an anionic group or a cationic group, the group being bonded directly or through an atomic group to a surface of the pigment, the second pigment is a pigment dispersible in an aqueous medium with the dispersant, and the dispersant is an ionic polymeric dispersant having a same polarity as that of the group bonded to the surface of the pigment or a nonionic polymeric dispersant.

Abstract: An ink set includes inks each containing a colorant and an aqueous medium, wherein in a fading test under conditions that cause fading corresponding to pseudo-indoor sunlight fading through a window for 3 years or more, the difference between respective images' &Dgr;E, the images being produced with the respective inks, is 10 or less in a CIELAB color space display system, and each of the images has a residual ratio of reflection density of 70% or more. By using the ink set including the color inks with which images having substantially the same fading &Dgr;E after long-term storage are produced, the color balance of a recorded image can be maintained after long-term storage.

Abstract: Disclosed herein is an ink set comprising two black inks the coloring materials for which are both pigments, wherein one black ink is cationic, and the other black ink is anionic.

Abstract: Provided is a black ink capable of mitigating the dependency on image quality of recording media and giving a high quality image stably, which comprises at least one salt selected from the group consisting of (M1)2SO4, CH3COO(M1), Ph_COO(M1), (M1)NO3, (M1)Cl, (M1)Br, (M1)I, (M1)2SO3 and (M1)2CO3, where M1 is an alkali metal, ammonium or organo-ammonium and Ph is a phenyl group, and a self dispersible carbon black.

Abstract: Disclosed herein is a printing method comprising a step of applying a liquid composition containing a cationic substance and an ink containing an anionic substance respectively on a recording medium so that the liquid composition and the ink are in contact with each other on the recording medium, wherein the ink contains a coloring material at a concentration of not higher than 1% and has a pH of 10.5 or higher. The printing method permits the provision of an image having excellent water fastness, image quality and resistance to bleeding on plain paper and can prevent the occurrence of whitish haze at a highlight part.

Abstract: Provided is a black ink capable of mitigating the dependency on image quality of recording media and giving a high quality image stably, which comprises at least one salt selected from the group consisting of (M1)2SO4, CH3COO(M1), Ph_COO(M1), (M1)NO3, (M1)Cl, (M1)Br, (M1)I, (M1)2SO3 and (M1)2CO3, where M1 is an alkali metal, ammonium or organo-ammonium and Ph is a phenyl group, and a self dispersible carbon black.

Abstract: Provided is a black ink capable of mitigating the dependency on image quality of recording media and giving a high quality image stably, which comprises at least one salt selected from the group consisting of (M1)2SO4, CH3COO(M1), Ph_COO(M1), (M1)NO3, (M1)Cl, (M1)Br, (M1)I, (M1)2SO3 and (M1)2CO3, where M1 is an alkali metal, ammonium or organo-ammonium and Ph is a phenyl group, and a self dispersible carbon black.

Abstract: Disclosed herein is a pigment ink comprising self-dispersing type carbon black to the surface of which at least one hydrophilic group is bonded through another atomic group, an aqueous medium, and a silicon compound. The pigment ink can form images excellent in fastness properties such as water fastness and light fastness and character quality, can be efficiently ejected when applied to ink-jet recording and can also be stably ejected from a recording head irrespective of recording head and printing environment.

Abstract: A method of forming a black image on a recording member includes the steps of providing each of a black ink having a first penetration rate and at least one color ink having a second penetration rate different from the first penetration rate, applying the at least one color ink to the recording member, and applying the black ink to the recording member after the at least one color ink has been absorbed into the recording member is disclosed. An ink-jet recording apparatus is also disclosed.

Abstract: The invention provides an ink comprising a coloring material, a solvent for dissolving or dispersing the coloring material, and an amphoteric polymer having both anionic and cationic groups. The invention also provides an ink-jet recording process and apparatus using such an ink.

Abstract: A liquid jet recording method includes applying thermal energy to liquid in a liquid passage to produce film boiling of the liquid to produce a bubble; permitting the bubble to communicate with ambience; wherein the liquid passage is not blocked in the communicating step.

Abstract: In a jet recording method, a recording material is placed in a path defined by a nozzle leading to an ejection outlet, and then heated by actuating a heater disposed within the nozzle to generate a bubble within the recording material, thus ejecting a droplet of the recording material out of the ejection outlet under the action of the bubble to be attached onto recording paper. As improvement, the recording material is pre-heated by actuating the heater before the heating for generating the bubble, and the generated bubble is caused to communicate with ambience. As a result, the ejection of the recording material droplet is stabilized without causing splash or mist.

Abstract: When a black image region is printed, the overall pixels in the region is printed by a black ink. Then, a cation type cyan ink which makes a coloring agent in the ink insoluble is printed on the pixels of a predetermined pattern. By this, the dye of the black ink is maintained near the surface of the printing medium to increase density of the black image. At the same time, for preventing variation of tone of the black image, the pixels of the predetermined pattern are printed by a yellow ink.

Abstract: Provided is an ink-jet recording process for forming a color image on a recording medium using a liquid formulation and a color ink in combination, wherein the liquid formulation contains a cationic polymer having a weight-average molecular weight in the range of from 400 to 1,400, and the liquid formulation and the ink are each ejected from a recording head having an ink ejection volume per dot of from 2 to 25 picolitters.

Abstract: There are provided a color image forming method with liquids, capable of ensuring sharpness and high density in basically all the color images, and a recording apparatus therefor. This invention employs a black ink of relatively superior diffusibility and color inks of relatively superior penetrability, different in color from the black ink, and is characterized by forming the boundary area of a black image area with the color inks instead of the black ink.

Abstract: Disclosed herein is an ink-jet recording process which comprises applying a first liquid at least containing a water-soluble resin having at least one carboxyl group or anhydride thereof, or sulfonic group per molecule to a recording medium and then applying an ink at least comprising water, an organic solvent, a dye, an alkali-soluble resin and an alkali to the portions where the first liquid has adhered, thereby forming an image. An ink set and an instrument for use in such a process are also disclosed.

Abstract: Disclosed herein is a water-based pigment ink comprising a coloring material composed of self-dispersing carbon black obtained by bonding at least one hydrophilic group directly or through another atomic group to the surface of carbon black, a humectant of the general formulaH--(CH.sub.2).sub.m --C--((CH.sub.2).sub.n OH).sub.3wherein m and n are independently an integer of from 1 to 5, and an aqueous medium composed of water and a water-soluble organic solvent.

Abstract: Disclosed herein is an ink set comprising in combination at least two inks of different colors, wherein at least one ink comprises a cationic dye and an amphoteric compound, and another ink of a color different from said one ink comprises an anionic dye and a water-soluble anionic polymer or nonionic polymer in addition to the dye.

Abstract: An ink including a dye; a liquid medium for dissolving the dye; and a polymer, wherein the surface tension and the viscosity of the ink respectively are 26.times.10.sup.-5 N/cm to 40.times.10.sup.-5 N/cm and 0.7.times.10.sup.-3 Pa.multidot.s to 12.times.10.sup.-3 Pa.multidot.s, and the forward contact angle with respect to a recording medium, on which an image will be printed, ranges from 60.degree. to 180.degree. at 25.degree. C. An ink jet recording method and recording apparatus employing the ink are also disclosed.

Abstract: In a jet recording method, a normally solid recording material is placed in a heat-melted state in a path defined by a nozzle leading to an ejection outlet and, in a recording step, is imparted with a thermal energy corresponding to a recording signal to generate a bubble, thus ejecting a droplet of the recording material out of the ejection outlet. As an improvement, prior to the recording step, the recording material is sucked or pressurized to be ejected out of the ejection outlet and, in the recording step, the bubble is communicated with ambience. As a result, the recording is started or resumed without discharge failure even after a long time of non-use or standing state.