Ricoh Company, Ltd.

Tomoko Maeda

Kiyofumi Nagai

Akihiko Gotoh

Kakuji Murakami

Hitoshi Arita

Nobutaka Osada

Tetsuya Kaneko

Akiko Bannai

Masayuki Koyano

Toshiroh Tokuno

An image recording method including: applying a pretreatment liquid on a surface of a recording material; and discharging a recording ink according to image signals to form an ink image on the pretreatment liquid on the surface of the recording material before the pretreatment liquid applied to the recording material has dried, wherein the recording ink includes a solvent and a component dispersed or dissolved in the solvent, wherein the pretreatment liquid includes a compound depressing at least one of the dispersibility and solubility of the component in the recording ink in an amount of 10 to 80% by weight based on total weight, and wherein the pretreatment liquid has a viscosity of from 100 to 10,000 mPa&#xb7;s at 25&#xb0; C.

Pretreatment liquid for recording material and image recording method using the pretreatment liquid

An ink composition including a colorant; and a solvent, wherein a zeta potential 2 between the colorant and a material selected from the group consisting of silicon, glass, silicon oxide, titanium oxide, chromium oxide, titanium nitride, silicon nitride, zirconium and polyimide is from 0 to &#x2212;50 mV at a pH of from 6.5 to 11.5. A corrosion inhibitor is preferably added to the ink composition to adjust the zeta potential 2. An ink cartridge containing the ink which optionally includes a recording head discharging the ink to form an image on a recording material, wherein the zeta potential 2 between the colorant in the ink and a material of the recording head contacting the ink is from 0 to &#x2212;50 mV at a pH of from 6.5 to 11.5. An inkjet recording apparatus including the ink cartridge and a carriage carrying the ink cartridge.

Ink composition and inkjet recording method and apparatus using the ink composition

An image recording method including: applying a pretreatment liquid on a surface of a recording material; and discharging a recording ink according to image signals to form an ink image on the pretreatment liquid on the surface of the recording material before the pretreatment liquid applied to the recording material has dried, wherein the recording ink includes a solvent and a component dispersed or dissolved in the solvent, wherein the pretreatment liquid includes a compound depressing at least one of the dispersibility and solubility of the component in the recording ink in an amount of 100 to 80% by weight based on total weight, and wherein the pretreatment liquid has a viscosity of from 10 to 10,000 mPa&middot;s at 25&deg; C.

An aqueous ink composition contains at least one pigment selected from the group consisting of a condensed azo pigment, a condensed polycyclic pigment, a phthalocyanine pigment, and a nickel complex azo pigment, at least an anionic surfactant with ethylene oxide group or a nonionic surfactant with ethylene oxide group as a dispersant, a wetting agent, a penetrating agent, and water, with the ink composition having a surface tension of 20 mN/m or more and less than 35 mN/m. A yellow ink containing at least one pigment selected from the group consisting of C.I. Pigment Yellow 128, C.I. Pigment Yellow 138, C.I. Pigment Yellow 151, C.I. Pigment Yellow 97, and C.I. Pigment Yellow 150, a magenta ink containing at least one pigment of C.I. Pigment Red 122 or C.I. Pigment Violet 19, a cyan ink containing at least one pigment of C.I. Pigment Blue 15:3 or C.I. Pigment Blue 15:4, each color ink further containing a specific anionic surfactant and a water-soluble organic solvent, and a black ink containing C.I. Pigment Black 7 are used together as a set of color ink compositions for ink-jet recording.

Aqueous ink composition

An ink composition including a colorant; and a solvent, wherein a zeta potential between the colorant and a material selected from the group consisting of silicon, glass, silicon oxide, titanium oxide, chromium oxide, titanium nitride, silicon nitride, zirconium and polyimide is from 0 to &minus;50 mV at a pH of from 6.5 to 11.5. A corrosion inhibitor is preferably added to the ink composition to adjust the zeta potential . An ink cartridge containing the ink which optionally includes a recording head discharging the ink to form an image on a recording material, wherein the zeta potential between the colorant in the ink and a material of the recording head contacting the ink is from 0 to &minus;50 mV at a pH of from 6.5 to 11.5. An inkjet recording apparatus including the ink cartridge and a carriage carrying the ink cartridge.

An ink for ink jet recording and an ink jet recording method which realize an image quality of laser printer on a plain paper in a one-pass printing mode under conditions of a volume of an ink droplet ejected being 5 to 43 Pico liter, a velocity of an ink droplet being 6 to 20 m/sec, frequency of 1 kHz and resolution of 300 dpi or more. The ink for ink jet recording is a penetrating type ink which includes (1) at least one humectant selected from glycerin, 1,3-butandiol, triethyleneglycol, 1,6-hexanediol, propyleneglycol, 1,5-pentanediol, diethyleneglycol, dipropyleneglycol, trimethylolpropane and trimethylolethane, (2) colorant contained in the amount of 6% by weight or more, (3) a polyol having 8 to 11 carbon atoms and glycolether, and an anionic surfactants or non-ionic surfactants, the ink has viscosity of 5 mPa&middot;s or more at 25&deg; C. and a surface tension of 40 mN/m or less.

Ink for ink jet recording, ink set for ink jet recording, method for ink jet recording, ink cartridge for ink jet recording, ink jet recording apparatus and recorded article

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Saitama, Japan

Tomoko Maeda