Ricoh Company, Ltd.

Koji Katsuragi

Tsutomu Maekawa

Yukitaka Watarai

Atsufumi Hanazawa

Tomohiro Nakagawa

Takashi Tamai

Masaki Kudo

Dongsik Jang

Hiroshi Goto

Hiroshi Gotou

Akihiko Gotoh

Yuusuke Koizuka

Keita Katoh

Hidefumi Nagashima

Yuuki Yokohama

Hisashi Habashi

Ichiroh Fujii

Haruki Saitoh

Ken Hasegawa

Yuichi Tanioku

A method of printing a stealth white image includes applying a stealth ink containing a red coloring material that emits visible light at exposure to ultraviolet radiation and a green coloring material that emits visible light at exposure to ultraviolet radiation to a substrate which contains a fluorescent brightener to form the stealth white image thereon, wherein the stealth white image demonstrates an a* value of from &#x2212;2.0 to 2.0 and a b* value of from &#x2212;10.0 to 0 at exposure to ultraviolet radiation having a wavelength of 370 nm according to CIE 1976 L*a*b* colorimetric system.

Method of printing stealth white image, set of substrate and stealth ink, and printing device

A liquid composition includes an inorganic particle and a multivalent metal salt, wherein the liquid composition has a tacking force of 50 mN or less in an area of cast-coated paper where the liquid composition is applied in an amount of 0.12 mg/cmfor the cast-coated paper followed by heating at 80 degrees C. for 15 seconds.

Liquid composition, device for applying liquid composition, image forming device, and image forming method

Provided is a liquid discharging apparatus including a liquid discharging unit configured to discharge a liquid, and a dummy discharge receptacle including an absorbing member configured to absorb a liquid dummy-discharged by the liquid discharging unit, wherein the liquid discharging unit discharges a liquid having a resin content of 5% by mass or greater, and wherein the absorbing member of the dummy discharge receptacle is formed of melamine foam.

Liquid discharging apparatus

A white ink includes a hollow resin particle, an organic solvent, an acrylic silicone resin, and water, wherein the acrylic silicone resin has a resin solubility parameter smaller than that of the hollow resin particle.

White ink, printed matter, method of printing, and device for printing

An image forming method includes applying white ink containing hollow resin particulate to a recording medium and contacting a heating roller having a diameter of 200 mm or less with a first surface of the recording medium.

Image forming method and image forming apparatus

A printing method includes applying a processing fluid to a recording medium and applying an ink to the recording medium, wherein the processing fluid contains a first nonionic resin including the following structure unit a-1, the first nonionic resin having a glass transition temperature of 15 degrees C. or lower, wherein the ink contains a second nonionic resin including the following structure unit a-1 and a coloring material 

Printing method and set of processing fluid and ink

An ink set includes a white ink including a hollow particle accounting for 5.0 to 25.0 percent by mass of the white ink and a non-white ink, wherein, in an infrared spectrum for a dried film of the white ink, a ratio (Y/X) of the maximum value Y in an absorption band of from 1720 to 1740 cmto the maximum value X in an absorption band of from 1590 to 1610 cm, is from 3.0 to 6.0, wherein the non-white ink has a surface tension of from 20.0 to 30.0 mN/m at a bubble lifetime of 1500 ms.

Ink set, white ink, recording method, and ink discharging device

Recorded matter includes a recording medium and an image on the recording medium. The image comprises a hollow resin including a copolymer of the structure unit represented by the following chemical formula 1 and the structure unit represented by the following chemical formula 2. Also, in an IR spectrum of the image, the image satisfies the following ratio: 3.0&#x2264;Y/X&#x2264;6.0, where X represents the absorbance of the image at the maximum absorption wavelength in a range of from 1,590 to 1,610 cmand Y represents the absorbance of the image at the maximum absorption wavelength in a range of from 1,720 to 1,740 cm. 

Recorded matter, ink for recorded matter, and ink

Provided is an ink set including: a first ink that is white and contains water, hollow resin particles, and at least one organic solvent; and a second ink that contains water and at least one organic solvent and is to be applied on a first image formed with the first ink to form a second image, wherein an average thickness difference (A&#x2212;B) between an average thickness (A) of the first image before the second ink is applied and an average thickness (B) of a white region in the first image after the second image is formed is 1 &#x3bc;m or greater but 3 &#x3bc;m or less.

Ink set, printing method, and printing apparatus

A white ink includes a hollow resin particle, one or more first organic solvents, an acrylic silicone-based resin, a surfactant; and water. The luminosity (L*) of each of a first dried film having a thickness of 2.2-2.8 &#x3bc;m prepared by drying the white ink at 70 degrees C. and a second dried film having a thickness of 2.2-2.8 &#x3bc;m prepared by drying the white ink at 90 degrees C. is 50 or greater and the decrease ratio of the luminosity (L*) of the second dried film to the first dried film is 10 percent or less.

White ink, ink set, and inkjet recording method

To provide an image forming set including: an aqueous ink including a colorant, a water-soluble organic solvent, and water; and a post-treatment liquid including a water-soluble organic solvent, water, and at least one of a urethane resin and an acrylic resin, wherein a solubility parameter of a mixed solution of the water-soluble organic solvent and the water in the post-treatment liquid is lower than a solubility parameter of a mixed solution of the water-soluble organic solvent and the water in the aqueous ink by 1.5 (cal/cm)or greater.

Image forming set, image forming apparatus, and image forming method

A treatment liquid, which contains a water-soluble organic solvent, at least two cationic resins, and water, wherein the cationic resins have a cationization degree of 4 meq/g or greater at pH of 4.0, and a repeating unit represented by the following structural formula 1: and the cationic resins have mutually different weight average molecular weights in the range of 5,000 to 25,000.

Treatment liquid, ink set, and inkjet recording method

To provide a treatment liquid for treating a recording medium, which contains a water-soluble organic solvent, a surfactant, water, and an amphoteric emulsion resin having a core-shell structure.

Treatment liquid for treating recording medium, image forming method and image forming apparatus

Provided is an image forming method, including: applying a treatment liquid to a recording medium; and applying a recording ink to the recording medium. The treatment liquid is free from a colorant, and contains an organic acid salt or a cationic resin or both thereof, a water-soluble organic solvent, and water. The water-soluble organic solvent contains one or more selected from sodium poly-&#x3b3;-glutamate, N-acyl fatty acid-sodium L-glutamate, sodium N-lauroyl-L-aspartate, and a compound represented by General Formula 1 below. The recording ink contains a colorant, a water-soluble organic solvent, a surfactant, a carboxyl group-containing resin, and water. 

To provide an image forming method, which contains: applying a treatment liquid onto a recording medium; and applying a recording ink onto the recording medium, wherein the treatment liquid contains a cationic resin having a cationic degree of 5 or higher, nonionic polyacryl amide, an alkali salt of a C12-C18 olefin-maleic acid copolymer, an organic solvent, a surfactant, and water, and wherein the recording ink contains a colorant, an organic solvent, a surfactant, and water.

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Kanagawa, Japan

Koji Katsuragi